diff --git a/.circleci/config.yml b/.circleci/config.yml
index 87236581a..2139fa94d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -9,7 +9,7 @@ version: 2.1
 parameters:
   docker-image-rev:
     type: string
-    default: "2"
+    default: "3"
 
 defaults:
 
diff --git a/.circleci/docker/Dockerfile.clang.ubuntu1904 b/.circleci/docker/Dockerfile.clang.ubuntu1904
index 3678afbed..0306dcf68 100644
--- a/.circleci/docker/Dockerfile.clang.ubuntu1904
+++ b/.circleci/docker/Dockerfile.clang.ubuntu1904
@@ -62,7 +62,7 @@ RUN git clone --recursive -b boost-1.69.0 https://github.com/boostorg/boost.git
     rm -rf /usr/src/boost
 
 # Z3
-RUN git clone --depth 1 -b z3-4.8.6 https://github.com/Z3Prover/z3.git \
+RUN git clone --depth 1 -b z3-4.8.7 https://github.com/Z3Prover/z3.git \
     /usr/src/z3; \
     cd /usr/src/z3; \
     python scripts/mk_make.py --prefix=/usr ; \
diff --git a/.circleci/osx_install_dependencies.sh b/.circleci/osx_install_dependencies.sh
index fadff605e..59e7c2234 100755
--- a/.circleci/osx_install_dependencies.sh
+++ b/.circleci/osx_install_dependencies.sh
@@ -43,13 +43,13 @@ then
   ./scripts/install_obsolete_jsoncpp_1_7_4.sh
 
   # z3
-  wget https://github.com/Z3Prover/z3/releases/download/z3-4.8.6/z3-4.8.6-x64-osx-10.14.6.zip
-  unzip z3-4.8.6-x64-osx-10.14.6.zip
-  rm -f z3-4.8.6-x64-osx-10.14.6.zip
-  cp z3-4.8.6-x64-osx-10.14.6/bin/libz3.a /usr/local/lib
-  cp z3-4.8.6-x64-osx-10.14.6/bin/z3 /usr/local/bin
-  cp z3-4.8.6-x64-osx-10.14.6/include/* /usr/local/include
-  rm -rf z3-4.8.6-x64-osx-10.14.6
+  wget https://github.com/Z3Prover/z3/releases/download/z3-4.8.7/z3-4.8.7-x64-osx-10.14.6.zip
+  unzip z3-4.8.7-x64-osx-10.14.6.zip
+  rm -f z3-4.8.7-x64-osx-10.14.6.zip
+  cp z3-4.8.7-x64-osx-10.14.6/bin/libz3.a /usr/local/lib
+  cp z3-4.8.7-x64-osx-10.14.6/bin/z3 /usr/local/bin
+  cp z3-4.8.7-x64-osx-10.14.6/include/* /usr/local/include
+  rm -rf z3-4.8.7-x64-osx-10.14.6
 
   # evmone
   wget https://github.com/ethereum/evmone/releases/download/v0.3.0/evmone-0.3.0-darwin-x86_64.tar.gz
diff --git a/test/libsolidity/smtCheckerTests/invariants/loop_array.sol b/test/libsolidity/smtCheckerTests/invariants/loop_array.sol
deleted file mode 100644
index 0f6937d36..000000000
--- a/test/libsolidity/smtCheckerTests/invariants/loop_array.sol
+++ /dev/null
@@ -1,19 +0,0 @@
-pragma experimental SMTChecker;
-
-contract Simple {
-	uint[] a;
-	function f(uint n) public {
-		uint i;
-		while (i < n)
-		{
-			a[i] = i;
-			++i;
-		}
-		require(n > 1);
-		// Assertion is safe but current solver version cannot solve it.
-		// Keep test for next solver release.
-		assert(a[n-1] > a[n-2]);
-	}
-}
-// ----
-// Warning: (273-296): Assertion violation happens here
diff --git a/test/libsolidity/smtCheckerTests/loops/while_loop_array_assignment_storage_storage.sol b/test/libsolidity/smtCheckerTests/loops/while_loop_array_assignment_storage_storage.sol
new file mode 100644
index 000000000..92d1ded3e
--- /dev/null
+++ b/test/libsolidity/smtCheckerTests/loops/while_loop_array_assignment_storage_storage.sol
@@ -0,0 +1,26 @@
+pragma experimental SMTChecker;
+
+contract LoopFor2 {
+	uint[] b;
+	uint[] c;
+
+	function testUnboundedForLoop(uint n) public {
+		b[0] = 900;
+		uint[] storage a = b;
+		require(n > 0 && n < 100);
+		uint i;
+		while (i < n) {
+			b[i] = i + 1;
+			c[i] = b[i];
+			++i;
+		}
+		// Fails as false positive.
+		assert(b[0] == c[0]);
+		assert(a[0] == 900);
+		assert(b[0] == 900);
+	}
+}
+// ----
+// Warning: (296-316): Assertion violation happens here
+// Warning: (320-339): Assertion violation happens here
+// Warning: (343-362): Assertion violation happens here