diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 8803a69fc260..0d3667f92023 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -165,17 +165,6 @@ bool is_supported_compression(const char *ext)
 	return false;
 }
 
-bool is_kmodule_extension(const char *ext)
-{
-	if (strncmp(ext, "ko", 2))
-		return false;
-
-	if (ext[2] == '\0' || (ext[2] == '.' && is_supported_compression(ext+3)))
-		return true;
-
-	return false;
-}
-
 bool is_kernel_module(const char *pathname)
 {
 	struct kmod_path m;
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 54dd03a490ce..88f345cc5be2 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -190,7 +190,6 @@ char dso__symtab_origin(const struct dso *dso);
 int dso__read_binary_type_filename(const struct dso *dso, enum dso_binary_type type,
 				   char *root_dir, char *filename, size_t size);
 bool is_supported_compression(const char *ext);
-bool is_kmodule_extension(const char *ext);
 bool is_kernel_module(const char *pathname);
 bool decompress_to_file(const char *ext, const char *filename, int output_fd);
 bool dso__needs_decompress(struct dso *dso);