diff --git a/dexpreopt/dexpreopt.go b/dexpreopt/dexpreopt.go
index 40644a3..511b840 100644
--- a/dexpreopt/dexpreopt.go
+++ b/dexpreopt/dexpreopt.go
@@ -581,7 +581,8 @@
 	}
 
 	for _, f := range global.PatternsOnSystemOther {
-		if makefileMatch(filepath.Join(SystemPartition, f), dexLocation) {
+		// See comment of SYSTEM_OTHER_ODEX_FILTER for details on the matching.
+		if makefileMatch("/"+f, dexLocation) || makefileMatch(filepath.Join(SystemPartition, f), dexLocation) {
 			return true
 		}
 	}
diff --git a/dexpreopt/dexpreopt_test.go b/dexpreopt/dexpreopt_test.go
index aca5e63..bf692fe 100644
--- a/dexpreopt/dexpreopt_test.go
+++ b/dexpreopt/dexpreopt_test.go
@@ -122,13 +122,12 @@
 				{module: productModule, expectedPartition: "product"},
 			},
 		},
-		// product/app/% only applies to product apps inside the system partition
 		{
 			patterns: []string{"app/%", "product/app/%"},
 			moduleTests: []moduleTest{
 				{module: systemModule, expectedPartition: "system_other/system"},
 				{module: systemProductModule, expectedPartition: "system_other/system/product"},
-				{module: productModule, expectedPartition: "product"},
+				{module: productModule, expectedPartition: "system_other/product"},
 			},
 		},
 	}
@@ -148,7 +147,7 @@
 			}
 
 			if rule.Installs().String() != wantInstalls.String() {
-				t.Errorf("\nwant installs:\n   %v\ngot:\n   %v", wantInstalls, rule.Installs())
+				t.Errorf("\npatterns: %v\nwant installs:\n   %v\ngot:\n   %v", test.patterns, wantInstalls, rule.Installs())
 			}
 		}
 	}