diff --git a/CMakeLists.txt b/CMakeLists.txt
index 561498c5d..958c24782 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -323,7 +323,11 @@ if(LIB_INSTALL_DIR)
 endif()
 
 if (NOT EXISTS "${MBEDTLS_FRAMEWORK_DIR}/CMakeLists.txt")
-    message(FATAL_ERROR "${MBEDTLS_FRAMEWORK_DIR}/CMakeLists.txt not found. Run `git submodule update --init` from the source tree to fetch the submodule contents.")
+    if (NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.git/")
+        message(FATAL_ERROR "${CMAKE_CURRENT_SOURCE_DIR}/.git/ not found. Please ensure you have downloaded a release version of Mbed TLS from GitHub.")
+    else ()
+        message(FATAL_ERROR "${MBEDTLS_FRAMEWORK_DIR}/CMakeLists.txt not found. Run `git submodule update --init` from the source tree to fetch the submodule contents.")
+    endif()
 endif()
 add_subdirectory(framework)
 
diff --git a/Makefile b/Makefile
index 71ef1bef0..07eb5567a 100644
--- a/Makefile
+++ b/Makefile
@@ -11,6 +11,19 @@ $(MBEDTLS_PATH)/framework/exported.make not found.
 Run `git submodule update --init` to fetch the submodule contents.
 This is a fatal error
         endef
+        ifeq (,$(wildcard .git))
+          define error_message
+$(MBEDTLS_PATH)/.git/ not found.
+Please ensure you have downloaded a release version of Mbed TLS from GitHub.
+This is a fatal error
+          endef
+        else
+          define error_message
+$(MBEDTLS_PATH)/framework/exported.make not found.
+Run `git submodule update --init` to fetch the submodule contents.
+This is a fatal error
+          endef
+        endif
         $(error $(error_message))
     endif
     include framework/exported.make