diff --git a/src/main/resources/xsl/ImvertCompiler/Imvert2validate-derivation.xsl b/src/main/resources/xsl/ImvertCompiler/Imvert2validate-derivation.xsl
index c10e80d3..9771def3 100644
--- a/src/main/resources/xsl/ImvertCompiler/Imvert2validate-derivation.xsl
+++ b/src/main/resources/xsl/ImvertCompiler/Imvert2validate-derivation.xsl
@@ -389,7 +389,7 @@
                 <xsl:sequence select="imf:report-warning($this, 
                     $min eq 1 and empty($applicable-values),
                     'Tagged value [1] not specified but required for [2]',($tv-name,imf:string-group($selected-stereotype)))"/>
-                <xsl:sequence select="imf:report-warning($this, 
+                <xsl:sequence select="imf:report-error($this, 
                     count($applicable-values) gt $max,
                     'Tagged value [1] specified too many times for [2]',($tv-name,imf:string-group($selected-stereotype)))"/>