diff --git a/osagetlang.sh b/osagetlang.sh
index f82c09a..44e0d63 100755
--- a/osagetlang.sh
+++ b/osagetlang.sh
@@ -1,6 +1,7 @@
 #!/usr/bin/env osascript
 
 use AppleScript version "2.4"
+use scripting additions
 use framework "Foundation"
 use framework "OSAKit"
 
@@ -9,7 +10,15 @@ on run args
 	set scpt_path to item 1 of args
 	set source_nsurl to current application's NSURL's fileURLWithPath:scpt_path
 	set the_script to current application's OSAScript's alloc()'s initWithContentsOfURL:source_nsurl |error|:(missing value)
-	if the_script is missing value then error "File or contained script is unreachable" number 1
+	if the_script is missing value then error "Script cannot be loaded by OSAScript" number 2
 	set osa_lang to the_script's language()'s |name| as text
+	if osa_lang is "AppleScript" then
+		#verify if it's really AppleScript (OSAScript thinks even a JPEG is an AppleScript file)
+		set cmd to "file --brief " & quoted form of scpt_path
+		set magic_file_type to do shell script cmd
+		if magic_file_type is not "AppleScript compiled" then
+			error "File is not an OSA script file (magic says: " & magic_file_type & ")" number 3
+		end if
+	end if
 	get osa_lang
 end run
diff --git a/test-files/no-as.scpt b/test-files/no-as.scpt
new file mode 100644
index 0000000..4af3705
--- /dev/null
+++ b/test-files/no-as.scpt
@@ -0,0 +1 @@
+This is a text-file, NOT an AppleScript file.
diff --git a/test.sh b/test.sh
index 3a915b2..8b534ab 100755
--- a/test.sh
+++ b/test.sh
@@ -138,6 +138,7 @@ lang_test "asdbg.scpt" "AppleScript Debugger" 0 "Get language of an AppleScript
 lang_test "js.scpt"    "JavaScript"           0 "Get language of an JavaScript file"
 lang_test "perl.scpt"  "Perl"                 1 "Get language of non-existing file"
 lang_test ""           ""                     1 "Get language without arguments"
+lang_test "no-as.scpt" ""                     1 "Get language of a non-AppleScript file"
 
 #--| Instrumentarium to generate a test-error.
 if (( TEST_ERROR == 1 )); then