diff --git a/org.eclipse.jdt.core.manipulation/core extension/org/eclipse/jdt/internal/corext/fix/ConvertForLoopOperation.java b/org.eclipse.jdt.core.manipulation/core extension/org/eclipse/jdt/internal/corext/fix/ConvertForLoopOperation.java
index 78f4ff4..4b4b076 100644
--- a/org.eclipse.jdt.core.manipulation/core extension/org/eclipse/jdt/internal/corext/fix/ConvertForLoopOperation.java
+++ b/org.eclipse.jdt.core.manipulation/core extension/org/eclipse/jdt/internal/corext/fix/ConvertForLoopOperation.java
@@ -24,6 +24,7 @@
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.dom.AST;
+import org.eclipse.jdt.core.dom.ASTMatcher;
 import org.eclipse.jdt.core.dom.ASTNode;
 import org.eclipse.jdt.core.dom.ArrayAccess;
 import org.eclipse.jdt.core.dom.Assignment;
@@ -540,7 +541,9 @@
 								ITypeBinding[] parms= methodBinding.getParameterTypes();
 								if (!fIsCollection || !GET_QUERY.equals(method.getName().getFullyQualifiedName()) ||
 										parms.length != 1 || !parms[0].getName().equals("int") || //$NON-NLS-1$
-										!fSizeMethodBinding.getDeclaringClass().equals(methodBinding.getDeclaringClass()))
+										!fSizeMethodBinding.getDeclaringClass().equals(methodBinding.getDeclaringClass()) ||
+										fSizeMethodAccess.getExpression() == null ||
+										!fSizeMethodAccess.getExpression().subtreeMatch(new ASTMatcher(), method.getExpression()))
 									throw new InvalidBodyError();
 								fGetMethodBinding= methodBinding;
 							} else {
diff --git a/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/CleanUpTest.java b/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/CleanUpTest.java
index c3002e1..3fcf087 100644
--- a/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/CleanUpTest.java
+++ b/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/CleanUpTest.java
@@ -4230,6 +4230,43 @@
 		assertRefactoringResultAsExpected(new ICompilationUnit[] {cu1}, new String[] {expected1});
 	}
 
+	public void testJava50ForLoopBug550672() throws Exception {
+		IPackageFragment pack1= fSourceFolder.createPackageFragment("test1", false, null);
+		StringBuilder buf= new StringBuilder();
+		buf.append("package test1;\n");
+		buf.append("import java.util.List;\n");
+		buf.append("import java.util.ArrayList;\n");
+		buf.append("public class ForeachTest {\n");
+		buf.append("    void foo(List list) {\n");
+        buf.append("        List<File> a = new ArrayList<>();\n");
+        buf.append("        List<File> b = new ArrayList<>();\n");
+        buf.append("        for (int i = 0; i < a.size(); i++) {\n");
+        buf.append("            System.out.print(a.get(i) + \" \" + b.get(i));\n");
+		buf.append("        }\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		ICompilationUnit cu1= pack1.createCompilationUnit("E1.java", buf.toString(), false, null);
+
+		enable(CleanUpConstants.CONTROL_STATMENTS_CONVERT_FOR_LOOP_TO_ENHANCED);
+
+		buf= new StringBuilder();
+		buf.append("package test1;\n");
+		buf.append("import java.util.List;\n");
+		buf.append("import java.util.ArrayList;\n");
+		buf.append("public class ForeachTest {\n");
+		buf.append("    void foo(List list) {\n");
+        buf.append("        List<File> a = new ArrayList<>();\n");
+        buf.append("        List<File> b = new ArrayList<>();\n");
+        buf.append("        for (int i = 0; i < a.size(); i++) {\n");
+        buf.append("            System.out.print(a.get(i) + \" \" + b.get(i));\n");
+		buf.append("        }\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		String expected1= buf.toString();
+
+		assertRefactoringResultAsExpected(new ICompilationUnit[] {cu1}, new String[] {expected1});
+	}
+
 	public void testJava50ForLoopBug154939() throws Exception {
 		IPackageFragment pack1= fSourceFolder.createPackageFragment("test1", false, null);
 		StringBuilder buf= new StringBuilder();
diff --git a/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/ConvertForLoopQuickFixTest.java b/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/ConvertForLoopQuickFixTest.java
index d43c199..a37a20d 100644
--- a/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/ConvertForLoopQuickFixTest.java
+++ b/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/ConvertForLoopQuickFixTest.java
@@ -1080,6 +1080,30 @@
 		assertCorrectLabels(proposals);
 	}
 
+	public void testMultipleCollectionsNotAccepted() throws Exception {
+		IPackageFragment pack1= fSourceFolder.createPackageFragment("test1", false, null);
+		StringBuilder buf= new StringBuilder();
+		buf.append("package test1;\n");
+		buf.append("import java.util.List;\n");
+		buf.append("import java.util.ArrayList;\n");
+		buf.append("public class A {\n");
+		buf.append("    public void foo(Map<String, String> map) {\n");
+        buf.append("        List<File> a = new ArrayList<>();\n");
+        buf.append("        List<File> b = new ArrayList<>();\n");
+        buf.append("        for (int i = 0; i < a.size(); i++) {\n");
+        buf.append("            System.out.print(a.get(i) + \" \" + b.get(i));\n");
+		buf.append("        }\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		ICompilationUnit cu= pack1.createCompilationUnit("A.java", buf.toString(), false, null);
+
+		List<IJavaCompletionProposal> proposals= fetchConvertingProposal(buf, cu);
+
+		assertNull(fConvertLoopProposal);
+
+		assertCorrectLabels(proposals);
+	}
+
 	public void testArrayAccessWithCollections() throws Exception {
 		IPackageFragment pack1= fSourceFolder.createPackageFragment("test1", false, null);
 		StringBuilder buf= new StringBuilder();