diff --git a/ext/opcache/Optimizer/zend_inference.c b/ext/opcache/Optimizer/zend_inference.c
index e108b7a4dd8..fa20795690c 100644
--- a/ext/opcache/Optimizer/zend_inference.c
+++ b/ext/opcache/Optimizer/zend_inference.c
@@ -3083,7 +3083,13 @@ static int zend_update_type_info(const zend_op_array *op_array,
 					}
 					j = zend_ssa_next_use(ssa_ops, ssa_ops[i].result_def, j);
 				}
-				UPDATE_SSA_TYPE(tmp, ssa_ops[i].op1_def);
+				if ((tmp & MAY_BE_ARRAY)
+				 && (tmp & (MAY_BE_ARRAY_KEY_LONG|MAY_BE_ARRAY_KEY_STRING))) {
+					UPDATE_SSA_TYPE(tmp, ssa_ops[i].op1_def);
+				} else {
+					/* invalid key type */
+					UPDATE_SSA_TYPE(t1, ssa_ops[i].op1_def);
+				}
 				COPY_SSA_OBJ_TYPE(ssa_ops[i].op1_use, ssa_ops[i].op1_def);
 			}
 			/* FETCH_LIST on a string behaves like FETCH_R on null */
diff --git a/ext/opcache/tests/ssa_bug_009.phpt b/ext/opcache/tests/ssa_bug_009.phpt
new file mode 100644
index 00000000000..a6248ff5bdd
--- /dev/null
+++ b/ext/opcache/tests/ssa_bug_009.phpt
@@ -0,0 +1,19 @@
+--TEST--
+Incorrect type inference
+--FILE--
+<?php
+class PHP_CodeCoverage
+{
+    private function addUncoveredFilesFromWhitelist()
+    {
+        foreach ($uncoveredFiles as $uncoveredFile) {
+            for ($i = 1; $i <= $lines; $i++) {
+                $data[$uncoveredFile][$i] = PHP_CodeCoverage_Driver::LINE_NOT_EXECUTED;
+            }
+        }
+    }
+}
+?>
+OK
+--EXPECT--
+OK