diff --git a/Source/build.cpp b/Source/build.cpp
index 9dec08ee..95245b45 100644
--- a/Source/build.cpp
+++ b/Source/build.cpp
@@ -2776,32 +2776,33 @@ int CEXEBuild::uninstall_generate()
     if (add_db_data((char *)m_unicon_data,unicondata_size) < 0)
       return PS_ERROR;
 #ifdef NSIS_CONFIG_CRC_SUPPORT
-    #ifdef NSIS_CONFIG_CRC_ANAL
-      crc=CRC32(crc,header_data_new,icon_offset);
-    #else
-      crc=CRC32(crc,header_data_new+512,icon_offset-512);
-    #endif
-    // This bunch of lines do CRC for the uninstaller icon data
-    unsigned char* seeker = m_unicon_data;
-    DWORD dwEndOfIcons = 0;
-    while (*seeker) {
-      DWORD dwSize = *(DWORD*)seeker;
-      seeker += sizeof(DWORD);
-      DWORD dwOffset = *(DWORD*)seeker;
-      seeker += sizeof(DWORD);
-      // Do CRC for icon data
-      crc=CRC32(crc,seeker,dwSize);
-      seeker += dwSize;
-      if (*seeker) {
-        // Do CRC for data between icons
-        crc=CRC32(crc,header_data_new+dwOffset+dwSize,(*(DWORD*)(seeker+sizeof(DWORD)))-dwOffset-dwSize);
-      }
-      else {
-        dwEndOfIcons = dwOffset+dwSize;
+    {
+      // "create" the uninstaller
+      LPBYTE uninst_header = (LPBYTE) malloc(exeheader_size_new);
+      if (!uninst_header)
+        return PS_ERROR;
+
+      memcpy(uninst_header, header_data_new, exeheader_size_new);
+
+      // patch the icons
+      LPBYTE seeker = m_unicon_data;
+      while (*seeker) {
+        DWORD dwSize = *(LPDWORD) seeker;
+        seeker += sizeof(DWORD);
+        DWORD dwOffset = *(LPDWORD) seeker;
+        seeker += sizeof(DWORD);
+        memcpy(uninst_header + dwOffset, seeker, dwSize);
+        seeker += dwSize;
       }
+
+#ifdef NSIS_CONFIG_CRC_ANAL
+      crc=CRC32(crc, uninst_header, exeheader_size_new);
+#else
+      crc=CRC32(crc, uninst_header + 512, exeheader_size_new - 512);
+#endif
+
+      free(uninst_header);
     }
-    // Done with icons, carry on
-    crc=CRC32(crc,header_data_new+dwEndOfIcons,exeheader_size_new-dwEndOfIcons);
 #endif
     fh.nsinst[0]=FH_INT1;
     fh.nsinst[1]=FH_INT2;
diff --git a/Source/util.cpp b/Source/util.cpp
index 7d5f9a48..c8341261 100644
--- a/Source/util.cpp
+++ b/Source/util.cpp
@@ -306,7 +306,7 @@ int generate_unicons_offsets(unsigned char* exeHeader, unsigned char* uninstIcon
 
   MY_ASSERT((int)rdIcons - (int)exeHeader > iNextSection, "corrupted EXE - invalid pointer");
 
-  unsigned char* seeker = uninstIconData;
+  MY_ASSERT(rdIcons->Header.NumberOfIdEntries == 0, "no icons found");
 
   for (i = 0; i < rdIcons->Header.NumberOfIdEntries; i++) { // Icons dir can't have named entries
     MY_ASSERT(!rdIcons->Entries[i].DataIsDirectory, "bad resource directory");
@@ -319,18 +319,38 @@ int generate_unicons_offsets(unsigned char* exeHeader, unsigned char* uninstIcon
 
     MY_ASSERT((int)rde - (int)exeHeader > iNextSection, "corrupted EXE - invalid pointer");
 
-    DWORD dwSize = *(DWORD*)seeker;
-    seeker += sizeof(DWORD);
-    MY_ASSERT(dwSize != rde->Size, "installer, uninstaller icon size mismatch - see the Icon instruction's documentation for more information");
+    // find icon to replace
+    LPBYTE seeker = uninstIconData;
+    while (*seeker) {
+      DWORD dwSize = *(DWORD*)seeker;
+      seeker += sizeof(DWORD);
+      DWORD dwOffset = *(DWORD*)seeker;
+      // if we haven't set the offset yet and the size is the same, it's a match
+      if (!dwOffset && dwSize == rde->Size)
+        break;
+
+      seeker += dwSize + sizeof(DWORD);
+
+      // reached the end of the list and no match
+      MY_ASSERT(!*seeker, "installer, uninstaller icon size mismatch - see the Icon instruction's documentation for more information");
+    }
+
     // Set offset
-    *(DWORD*)seeker = rde->OffsetToData + DWORD(rdRoot) - dwResourceSectionVA - DWORD(exeHeader);
+    *(LPDWORD) seeker = rde->OffsetToData + DWORD(rdRoot) - dwResourceSectionVA - DWORD(exeHeader);
 
     MY_ASSERT(*(int*)seeker > iNextSection || *(int*)seeker < (int)rdRoot - (int)exeHeader, "invalid data offset - icon resource probably compressed");
-    
-    seeker += sizeof(DWORD) + dwSize;
   }
-  MY_ASSERT(i == 0, "no icons found");
-  MY_ASSERT(*(DWORD*)seeker != 0, "number of icons doesn't match");
+
+  LPBYTE seeker = uninstIconData;
+  while (*seeker) {
+    DWORD dwSize = *(DWORD*)seeker;
+    seeker += sizeof(DWORD);
+    DWORD dwOffset = *(DWORD*)seeker;
+    seeker += sizeof(DWORD);
+    // offset isn't set which means we found no match for this one
+    MY_ASSERT(!dwOffset, "number of icons doesn't match");
+    seeker += dwSize;
+  }
 
   return PIMAGE_RESOURCE_DATA_ENTRY(PRESOURCE_DIRECTORY(rdIcons->Entries[0].OffsetToDirectory + DWORD(rdRoot))->Entries[0].OffsetToData + DWORD(rdRoot))->OffsetToData + DWORD(rdRoot) - dwResourceSectionVA - DWORD(exeHeader);
 }