diff --git a/main.go b/main.go
index 6ead7a0..238847a 100644
--- a/main.go
+++ b/main.go
@@ -1880,7 +1880,10 @@ func filterForwardBuildFlags(flags []string) (filtered []string, firstUnknown st
 		arg := flags[i]
 		name := arg
 		if i := strings.IndexByte(arg, '='); i > 0 {
-			name = arg[:i]
+			name = arg[:i] // "-name=value" to "-name"
+		}
+		if strings.HasPrefix(name, "--") {
+			name = name[1:] // "--name" to "-name"
 		}
 
 		buildFlag := forwardBuildFlags[name]
diff --git a/testdata/scripts/imports.txt b/testdata/scripts/imports.txt
index e21051a..4d83b75 100644
--- a/testdata/scripts/imports.txt
+++ b/testdata/scripts/imports.txt
@@ -36,8 +36,9 @@ go build -tags buildtag
 exec ./main
 cmp stdout main.stdout
 
-# Also check that -literals doesn't break anything
-garble -literals build -tags buildtag
+# Check that -literals doesn't break anything.
+# Also check that a different form of -tags still works.
+garble -literals build --tags=buildtag
 exec ./main
 cmp stdout main.stdout