diff --git a/code/renderergl1/tr_shader.c b/code/renderergl1/tr_shader.c
index de3a45c4..103d329f 100644
--- a/code/renderergl1/tr_shader.c
+++ b/code/renderergl1/tr_shader.c
@@ -1010,8 +1010,8 @@ static qboolean ParseStage( shaderStage_t *stage, char **text )
 				token = COM_ParseExt( text, qfalse );
 				if ( token[0] == 0 )
 					break;
-				strcat( buffer, token );
-				strcat( buffer, " " );
+				Q_strcat( buffer, sizeof (buffer), token );
+				Q_strcat( buffer, sizeof (buffer), " " );
 			}
 
 			ParseTexMod( buffer, stage );
diff --git a/code/renderergl2/tr_shader.c b/code/renderergl2/tr_shader.c
index ed8212d2..cbb01121 100644
--- a/code/renderergl2/tr_shader.c
+++ b/code/renderergl2/tr_shader.c
@@ -1265,8 +1265,8 @@ static qboolean ParseStage( shaderStage_t *stage, char **text )
 				token = COM_ParseExt( text, qfalse );
 				if ( token[0] == 0 )
 					break;
-				strcat( buffer, token );
-				strcat( buffer, " " );
+				Q_strcat( buffer, sizeof (buffer), token );
+				Q_strcat( buffer, sizeof (buffer), " " );
 			}
 
 			ParseTexMod( buffer, stage );