diff --git a/Changelog.md b/Changelog.md
index 8f3bfff90..997c40697 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -91,6 +91,9 @@ Compiler Features:
  * Code Generator: Allocate and free local variables according to their scope.
  * Removed ``pragma experimental "v0.5.0";``.
 
+Critical Bugfixes:
+ * Code Generator: Properly perform cleanup for exponentiation and non-256 bit types.
+
 Bugfixes:
  * Build System: Support versions of CVC4 linked against CLN instead of GMP. In case of compilation issues due to the experimental SMT solver support, the solvers can be disabled when configuring the project with CMake using ``-DUSE_CVC4=OFF`` or ``-DUSE_Z3=OFF``.
  * Tests: Fix chain parameters to make ipc tests work with newer versions of cpp-ethereum.
diff --git a/docs/bugs.json b/docs/bugs.json
index cf03adfe1..b629d4854 100644
--- a/docs/bugs.json
+++ b/docs/bugs.json
@@ -1,4 +1,11 @@
 [
+    {
+        "name": "ExpCleanupZero",
+        "summary": "Using exponentiating with types shorter than 256 bits and zero as base can result in unexpected values.",
+        "description": "As defined by the EVM, 0 ** 0 is one. Solidity does not always remove dirty higher order bits of types that are smaller than 256 bits before applying an operation because it does not matter if the cleanup is performed before or after the operation. This is true for EXP except for the case where the base is zero, which was overlooked.",
+        "fixed": "0.5.0",
+        "severity": "high"
+    },
     {
         "name": "EventStructWrongData",
         "summary": "Using structs in events logged wrong data.",
diff --git a/docs/bugs_by_version.json b/docs/bugs_by_version.json
index ab200036b..1d41626ea 100644
--- a/docs/bugs_by_version.json
+++ b/docs/bugs_by_version.json
@@ -1,6 +1,7 @@
 {
     "0.1.0": {
         "bugs": [
+            "ExpCleanupZero",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
             "SkipEmptyStringLiteral",
@@ -18,6 +19,7 @@
     },
     "0.1.1": {
         "bugs": [
+            "ExpCleanupZero",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
             "SkipEmptyStringLiteral",
@@ -35,6 +37,7 @@
     },
     "0.1.2": {
         "bugs": [
+            "ExpCleanupZero",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
             "SkipEmptyStringLiteral",
@@ -52,6 +55,7 @@
     },
     "0.1.3": {
         "bugs": [
+            "ExpCleanupZero",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
             "SkipEmptyStringLiteral",
@@ -69,6 +73,7 @@
     },
     "0.1.4": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
@@ -87,6 +92,7 @@
     },
     "0.1.5": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
@@ -105,6 +111,7 @@
     },
     "0.1.6": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
@@ -124,6 +131,7 @@
     },
     "0.1.7": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
@@ -143,6 +151,7 @@
     },
     "0.2.0": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
@@ -162,6 +171,7 @@
     },
     "0.2.1": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
@@ -181,6 +191,7 @@
     },
     "0.2.2": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "ECRecoverMalformedInput",
@@ -200,6 +211,7 @@
     },
     "0.3.0": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -219,6 +231,7 @@
     },
     "0.3.1": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -237,6 +250,7 @@
     },
     "0.3.2": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -255,6 +269,7 @@
     },
     "0.3.3": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -272,6 +287,7 @@
     },
     "0.3.4": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -289,6 +305,7 @@
     },
     "0.3.5": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -306,6 +323,7 @@
     },
     "0.3.6": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -321,6 +339,7 @@
     },
     "0.4.0": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -336,6 +355,7 @@
     },
     "0.4.1": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -351,6 +371,7 @@
     },
     "0.4.10": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -362,6 +383,7 @@
     },
     "0.4.11": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -372,6 +394,7 @@
     },
     "0.4.12": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -381,6 +404,7 @@
     },
     "0.4.13": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -390,6 +414,7 @@
     },
     "0.4.14": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue"
@@ -398,6 +423,7 @@
     },
     "0.4.15": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector"
         ],
@@ -405,6 +431,7 @@
     },
     "0.4.16": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector"
         ],
@@ -412,6 +439,7 @@
     },
     "0.4.17": {
         "bugs": [
+            "ExpCleanupZero",
             "EventStructWrongData",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector"
@@ -420,6 +448,7 @@
     },
     "0.4.18": {
         "bugs": [
+            "ExpCleanupZero",
             "EventStructWrongData",
             "NestedArrayFunctionCallDecoder"
         ],
@@ -427,6 +456,7 @@
     },
     "0.4.19": {
         "bugs": [
+            "ExpCleanupZero",
             "EventStructWrongData",
             "NestedArrayFunctionCallDecoder"
         ],
@@ -434,6 +464,7 @@
     },
     "0.4.2": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -448,6 +479,7 @@
     },
     "0.4.20": {
         "bugs": [
+            "ExpCleanupZero",
             "EventStructWrongData",
             "NestedArrayFunctionCallDecoder"
         ],
@@ -455,6 +487,7 @@
     },
     "0.4.21": {
         "bugs": [
+            "ExpCleanupZero",
             "EventStructWrongData",
             "NestedArrayFunctionCallDecoder"
         ],
@@ -462,6 +495,7 @@
     },
     "0.4.22": {
         "bugs": [
+            "ExpCleanupZero",
             "EventStructWrongData",
             "OneOfTwoConstructorsSkipped"
         ],
@@ -469,18 +503,21 @@
     },
     "0.4.23": {
         "bugs": [
+            "ExpCleanupZero",
             "EventStructWrongData"
         ],
         "released": "2018-04-19"
     },
     "0.4.24": {
         "bugs": [
+            "ExpCleanupZero",
             "EventStructWrongData"
         ],
         "released": "2018-05-16"
     },
     "0.4.3": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -494,6 +531,7 @@
     },
     "0.4.4": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -506,6 +544,7 @@
     },
     "0.4.5": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -519,6 +558,7 @@
     },
     "0.4.6": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -531,6 +571,7 @@
     },
     "0.4.7": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -542,6 +583,7 @@
     },
     "0.4.8": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",
@@ -553,6 +595,7 @@
     },
     "0.4.9": {
         "bugs": [
+            "ExpCleanupZero",
             "NestedArrayFunctionCallDecoder",
             "ZeroFunctionSelector",
             "DelegateCallReturnValue",