diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/for_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/for_declaration_err.sol
new file mode 100644
index 000000000..ddb5faa9f
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/for_declaration_err.sol
@@ -0,0 +1,38 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal pure {
+        S storage c;
+        assembly {
+            for {} eq(0,0) { c_slot := s_slot } {}
+        }
+        c;
+    }
+    function g() internal pure {
+        S storage c;
+        assembly {
+            for {} eq(0,1) { c_slot := s_slot } {}
+        }
+        c;
+    }
+    function h() internal pure {
+        S storage c;
+        assembly {
+            for {} eq(0,0) {} { c_slot := s_slot }
+        }
+        c;
+    }
+    function i() internal pure {
+        S storage c;
+        assembly {
+            for {} eq(0,1) {} { c_slot := s_slot }
+        }
+        c;
+    }
+}
+// ----
+// TypeError: (189-190): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (340-341): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (491-492): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (642-643): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/for_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/for_declaration_fine.sol
new file mode 100644
index 000000000..19a58b234
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/for_declaration_fine.sol
@@ -0,0 +1,19 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal pure {
+        S storage c;
+        assembly {
+            for { c_slot := s_slot } iszero(0) {} {}
+        }
+        c;
+    }
+    function g() internal pure {
+        S storage c;
+        assembly {
+            for { c_slot := s_slot } iszero(1) {} {}
+        }
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/if_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/if_declaration_err.sol
new file mode 100644
index 000000000..1d4302755
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/if_declaration_err.sol
@@ -0,0 +1,13 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f(bool flag) internal pure {
+        S storage c;
+        assembly {
+            if flag { c_slot := s_slot }
+        }
+        c;
+    }
+}
+// ----
+// TypeError: (188-189): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/returning_function_declaration.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/returning_function_declaration.sol
new file mode 100644
index 000000000..180feb770
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/returning_function_declaration.sol
@@ -0,0 +1,15 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal pure {
+        S storage c;
+        // this should warn about unreachable code, but currently function flow is ignored
+        assembly {
+            function f() { return(0, 0) }
+            f()
+            c_slot := s_slot
+        }
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/reverting_function_declaration.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/reverting_function_declaration.sol
new file mode 100644
index 000000000..bba9daf34
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/reverting_function_declaration.sol
@@ -0,0 +1,15 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal pure {
+        S storage c;
+        // this could be allowed, but currently control flow for functions is not analysed
+        assembly {
+            function f() { revert(0, 0) }
+            f()
+        }
+        c;
+    }
+}
+// ----
+// TypeError: (287-288): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/stub_declaration.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/stub_declaration.sol
new file mode 100644
index 000000000..c3f240915
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/stub_declaration.sol
@@ -0,0 +1,12 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal pure {
+        S storage c;
+        assembly {
+            c_slot := s_slot
+        }
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/switch_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/switch_declaration_err.sol
new file mode 100644
index 000000000..72884e741
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/switch_declaration_err.sol
@@ -0,0 +1,33 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f(uint256 a) internal pure {
+        S storage c;
+        assembly {
+            switch a
+            case 0 { c_slot := s_slot }
+        }
+        c;
+    }
+    function g(bool flag) internal pure {
+        S storage c;
+        assembly {
+            switch flag
+            case 0 { c_slot := s_slot }
+            case 1 { c_slot := s_slot }
+        }
+        c;
+    }
+    function h(uint256 a) internal pure {
+        S storage c;
+        assembly {
+            switch a
+            case 0 { c_slot := s_slot }
+            default { return(0,0) }
+        }
+        c;
+    }
+}
+// ----
+// TypeError: (208-209): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (421-422): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/switch_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/switch_declaration_fine.sol
new file mode 100644
index 000000000..d72310924
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly/switch_declaration_fine.sol
@@ -0,0 +1,31 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f(uint256 a) internal pure {
+        S storage c;
+        assembly {
+            switch a
+            default { c_slot := s_slot }
+        }
+        c;
+    }
+    function g(bool flag) internal pure {
+        S storage c;
+        assembly {
+            switch flag
+            case 0 { c_slot := s_slot }
+            default { c_slot := s_slot }
+        }
+        c;
+    }
+    function h(uint256 a) internal pure {
+        S storage c;
+        assembly {
+            switch a
+            case 0 { revert(0, 0) }
+            default { c_slot := s_slot }
+        }
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/dowhile_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/dowhile_declaration_err.sol
new file mode 100644
index 000000000..25654b1dd
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/dowhile_declaration_err.sol
@@ -0,0 +1,66 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view {
+        S storage c;
+        do {
+            break;
+            c = s;
+        } while(false);
+        c;
+    }
+    function g() internal view {
+        S storage c;
+        do {
+            if (s.f) {
+                continue;
+                c = s;
+            }
+            else {
+            }
+        } while(false);
+        c;
+    }
+    function h() internal view {
+        S storage c;
+        do {
+            if (s.f) {
+                break;
+            }
+            else {
+                c = s;
+            }
+        } while(false);
+        c;
+    }
+    function i() internal view {
+        S storage c;
+        do {
+            if (s.f) {
+                continue;
+            }
+            else {
+                c = s;
+            }
+        } while(false);
+        c;
+    }
+    function j() internal view {
+        S storage c;
+        do {
+            continue;
+            c = s;
+        } while(false);
+        c;
+    }
+}
+// ----
+// TypeError: (184-185): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+//  Warning: (145-150): Unreachable code.
+// Warning: (168-173): Unreachable code.
+// TypeError: (411-412): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// Warning: (325-330): Unreachable code.
+// TypeError: (635-636): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (862-863): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (1011-1012): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+//  Warning: (972-977): Unreachable code.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/dowhile_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/dowhile_declaration_fine.sol
new file mode 100644
index 000000000..40ddc3777
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/dowhile_declaration_fine.sol
@@ -0,0 +1,44 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view {
+        S storage c;
+        do {} while((c = s).f);
+        c;
+    }
+    function g() internal view {
+        S storage c;
+        do { c = s; } while(false);
+        c;
+    }
+    function h() internal view {
+        S storage c;
+        c = s;
+        do {} while(false);
+        c;
+    }
+    function i() internal view {
+        S storage c;
+        do {} while(false);
+        c = s;
+        c;
+    }
+    function j() internal view {
+        S storage c;
+        do {
+            c = s;
+            break;
+        } while(false);
+        c;
+    }
+    function k() internal view {
+        S storage c;
+        do {
+            c = s;
+            continue;
+        } while(false);
+        c;
+    }
+}
+// ----
+// Warning: (606-611): Unreachable code.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/for_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/for_declaration_err.sol
new file mode 100644
index 000000000..e93d9798f
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/for_declaration_err.sol
@@ -0,0 +1,20 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view {
+        S storage c;
+        for(;; c = s) {
+        }
+        c;
+    }
+    function g() internal view {
+        S storage c;
+        for(;;) {
+            c = s;
+        }
+        c;
+    }
+}
+// ----
+//TypeError: (143-144): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (261-262): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/for_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/for_declaration_fine.sol
new file mode 100644
index 000000000..b3e9f46d1
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/for_declaration_fine.sol
@@ -0,0 +1,17 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view {
+        S storage c;
+        for(c = s;;) {
+        }
+        c;
+    }
+    function g() internal view {
+        S storage c;
+        for(; (c = s).f;) {
+        }
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/if_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/if_declaration_err.sol
new file mode 100644
index 000000000..7da6bef92
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/if_declaration_err.sol
@@ -0,0 +1,22 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f(bool flag) internal {
+        S storage c;
+        if (flag) c = s;
+        c;
+    }
+    function g(bool flag) internal {
+        S storage c;
+        if (flag) c = s;
+        else
+        {
+            if (!flag) c = s;
+            else s.f = true;
+        }
+        c;
+    }
+}
+// ----
+// TypeError: (138-139): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (330-331): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/if_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/if_declaration_fine.sol
new file mode 100644
index 000000000..5d3a6d5bd
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/if_declaration_fine.sol
@@ -0,0 +1,39 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f(bool flag) internal view {
+        S storage c;
+        if (flag) c = s;
+        else c = s;
+        c;
+    }
+    function g(bool flag) internal view {
+        S storage c;
+        if (flag) c = s;
+        else { c = s; }
+        c;
+    }
+    function h(bool flag) internal view {
+        S storage c;
+        if (flag) c = s;
+        else
+        {
+            if (!flag) c = s;
+            else c = s;
+        }
+        c;
+    }
+    function i() internal view {
+        S storage c;
+        if ((c = s).f) {
+        }
+        c;
+    }
+    function j() internal view {
+        S storage c;
+        if ((c = s).f && !(c = s).f) {
+        }
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/modifier_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/modifier_declaration_fine.sol
new file mode 100644
index 000000000..6df4939cf
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/modifier_declaration_fine.sol
@@ -0,0 +1,20 @@
+contract C {
+    modifier revertIfNoReturn() {
+        _;
+        revert();
+    }
+    modifier ifFlag(bool flag) {
+        if (flag)
+            _;
+    }
+    struct S { uint a; }
+    S s;
+    function f(bool flag) revertIfNoReturn() internal view {
+        if (flag) s;
+    }
+    function g(bool flag) revertIfNoReturn() ifFlag(flag) internal view {
+        s;
+    }
+
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/revert_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/revert_declaration_fine.sol
new file mode 100644
index 000000000..5cb580528
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/revert_declaration_fine.sol
@@ -0,0 +1,11 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function g(bool flag) internal view {
+        S storage c;
+        if (flag) c = s;
+        else revert();
+        s;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/short_circuit_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/short_circuit_declaration_err.sol
new file mode 100644
index 000000000..a6dd300ce
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/short_circuit_declaration_err.sol
@@ -0,0 +1,24 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view {
+        S storage c;
+        false && (c = s).f;
+        c;
+    }
+    function g() internal view {
+        S storage c;
+        true || (c = s).f;
+        c;
+    }
+    function h() internal view {
+        S storage c;
+        // expect error, although this is always fine
+        true && (false || (c = s).f);
+        c;
+    }
+}
+// ----
+// TypeError: (137-138): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+//  TypeError: (235-236): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+//  TypeError: (398-399): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/short_circuit_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/short_circuit_declaration_fine.sol
new file mode 100644
index 000000000..e8ad5e485
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/short_circuit_declaration_fine.sol
@@ -0,0 +1,15 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view {
+        S storage c;
+        (c = s).f && false;
+        c;
+    }
+    function g() internal view {
+        S storage c;
+        (c = s).f || true;
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/smoke_declaration.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/smoke_declaration.sol
new file mode 100644
index 000000000..f820456e1
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/smoke_declaration.sol
@@ -0,0 +1,17 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal pure {}
+    function g() internal view { s; }
+    function h() internal view {
+        S storage c;
+        c = s;
+        c;
+    }
+    function i() internal view {
+        S storage c;
+        (c) = s;
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/ternary_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/ternary_declaration_err.sol
new file mode 100644
index 000000000..3b4552f86
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/ternary_declaration_err.sol
@@ -0,0 +1,17 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f(bool flag) internal view {
+        S storage c;
+        flag ? (c = s).f : false;
+        c;
+    }
+    function g(bool flag) internal view {
+        S storage c;
+        flag ? false : (c = s).f;
+        c;
+    }
+}
+// ----
+// TypeError: (152-153): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (266-267): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/ternary_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/ternary_declaration_fine.sol
new file mode 100644
index 000000000..1dd8d2f57
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/ternary_declaration_fine.sol
@@ -0,0 +1,20 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f(bool flag) internal view {
+        S storage c;
+        flag ? c = s : c = s;
+        c;
+    }
+    function g(bool flag) internal view {
+        S storage c;
+        flag ? c = s : (c = s);
+        c;
+    }
+    function h(bool flag) internal view {
+        S storage c;
+        flag ? (c = s).f : (c = s).f;
+        c;
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/try_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/try_declaration_err.sol
new file mode 100644
index 000000000..ca43dc346
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/try_declaration_err.sol
@@ -0,0 +1,42 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function ext() external {}
+    function f() internal
+    {
+        S storage r;
+        try this.ext() { }
+        catch (bytes memory) { r = s; }
+        r;
+    }
+    function g() internal
+    {
+        S storage r;
+        try this.ext() { r = s; }
+        catch (bytes memory) { }
+        r;
+    }
+    function h() internal
+    {
+        S storage r;
+        try this.ext() {}
+        catch Error (string memory) { r = s; }
+        catch (bytes memory) { r = s; }
+        r;
+    }
+    function i() internal
+    {
+        S storage r;
+        try this.ext() { r = s; }
+        catch (bytes memory) { r; }
+        r = s;
+        r;
+    }
+}
+// ====
+// EVMVersion: >=byzantium
+// ----
+// TypeError: (206-207): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (343-344): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (526-527): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (653-654): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/try_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/try_declaration_fine.sol
new file mode 100644
index 000000000..6834525d5
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/try_declaration_fine.sol
@@ -0,0 +1,30 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function ext() external { }
+    function f() internal
+    {
+        S storage r;
+        try this.ext() { r = s; }
+        catch (bytes memory) { r = s; }
+        r;
+    }
+    function g() internal
+    {
+        S storage r;
+        try this.ext() { r = s; }
+        catch Error (string memory) { r = s; }
+        catch (bytes memory) { r = s; }
+        r;
+    }
+    function h() internal
+    {
+        S storage r;
+        try this.ext() { }
+        catch (bytes memory) { }
+        r = s;
+        r;
+    }
+}
+// ====
+// EVMVersion: >=byzantium
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/tuple_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/tuple_declaration_fine.sol
new file mode 100644
index 000000000..e2e274196
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/tuple_declaration_fine.sol
@@ -0,0 +1,17 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view returns (S storage, uint) {
+      return (s,2);
+    }
+    function g() internal view {
+        uint a;
+        S storage c;
+        (c, a) = f();
+        c;
+    }
+    function h() internal view {
+        (s, s);
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/while_declaration_err.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/while_declaration_err.sol
new file mode 100644
index 000000000..cd6fee8db
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/while_declaration_err.sol
@@ -0,0 +1,13 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view {
+        S storage c;
+        while(false) {
+            c = s;
+        }
+        c;
+    }
+}
+// ----
+// TypeError: (161-162): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
diff --git a/test/libsolidity/syntaxTests/controlFlow/storageReturn/while_declaration_fine.sol b/test/libsolidity/syntaxTests/controlFlow/storageReturn/while_declaration_fine.sol
new file mode 100644
index 000000000..20e72e5db
--- /dev/null
+++ b/test/libsolidity/syntaxTests/controlFlow/storageReturn/while_declaration_fine.sol
@@ -0,0 +1,25 @@
+contract C {
+    struct S { bool f; }
+    S s;
+    function f() internal view {
+        S storage c;
+        while((c = s).f) {
+        }
+        c;
+    }
+    function g() internal view {
+        S storage c;
+        c = s;
+        while(false) {
+        }
+        c;
+    }
+    function h() internal view {
+        S storage c;
+        while(false) {
+        }
+        c = s;
+        c;
+    }
+}
+// ----