diff --git a/src/gallium/drivers/iris/iris_context.h b/src/gallium/drivers/iris/iris_context.h
index fb4423957ca..42cad5e8551 100644
--- a/src/gallium/drivers/iris/iris_context.h
+++ b/src/gallium/drivers/iris/iris_context.h
@@ -260,9 +260,8 @@ struct iris_uncompiled_shader {
 
    struct pipe_stream_output_info stream_output;
 
-   /* The serialized NIR (for the disk cache) and size in bytes. */
-   void *ir_cache_binary;
-   uint32_t ir_cache_binary_size;
+   /* A SHA1 of the serialized NIR for the disk cache. */
+   unsigned char nir_sha1[20];
 
    unsigned program_id;
 
diff --git a/src/gallium/drivers/iris/iris_disk_cache.c b/src/gallium/drivers/iris/iris_disk_cache.c
index 2b022aff66a..eac01048122 100644
--- a/src/gallium/drivers/iris/iris_disk_cache.c
+++ b/src/gallium/drivers/iris/iris_disk_cache.c
@@ -61,16 +61,13 @@ iris_disk_cache_compute_key(struct disk_cache *cache,
    memcpy(&prog_key, orig_prog_key, prog_key_size);
    brw_prog_key_set_id(&prog_key, stage, 0);
 
-   uint32_t data_size = prog_key_size + ish->ir_cache_binary_size;
+   uint8_t data[sizeof(prog_key) + sizeof(ish->nir_sha1)];
+   uint32_t data_size = prog_key_size + sizeof(ish->nir_sha1);
 
-   void *data = malloc(data_size);
-   memcpy(data, &prog_key, prog_key_size);
-   memcpy(data + prog_key_size, ish->ir_cache_binary,
-          ish->ir_cache_binary_size);
+   memcpy(data, ish->nir_sha1, sizeof(ish->nir_sha1));
+   memcpy(data + sizeof(ish->nir_sha1), &prog_key, prog_key_size);
 
    disk_cache_compute_key(cache, data, data_size, cache_key);
-
-   free(data);
 }
 
 /**
diff --git a/src/gallium/drivers/iris/iris_program.c b/src/gallium/drivers/iris/iris_program.c
index a5cd987664f..60f45eec629 100644
--- a/src/gallium/drivers/iris/iris_program.c
+++ b/src/gallium/drivers/iris/iris_program.c
@@ -1506,9 +1506,7 @@ iris_create_uncompiled_shader(struct pipe_context *ctx,
       struct blob blob;
       blob_init(&blob);
       nir_serialize(&blob, ish->nir);
-      ish->ir_cache_binary = malloc(blob.size);
-      ish->ir_cache_binary_size = blob.size;
-      memcpy(ish->ir_cache_binary, blob.data, blob.size);
+      _mesa_sha1_compute(blob.data, blob.size, ish->nir_sha1);
       blob_finish(&blob);
    }