diff --git a/MathRenderer.php b/MathRenderer.php
index 2f0b16cdf..925321fbd 100644
--- a/MathRenderer.php
+++ b/MathRenderer.php
@@ -137,7 +137,7 @@ abstract class MathRenderer {
 	public function getInputHash() {
 		// TODO: What happens if $tex is empty?
 		$dbr = wfGetDB( DB_SLAVE );
-		return $dbr->encodeBlob( pack( "H32", md5( $this->tex ) ) ); # Binary packed, not hex
+		return $dbr->encodeBlob( pack( "H32", md5( $this->getUserInputTex() ) ) ); # Binary packed, not hex
 	}
 
 	/**
@@ -443,5 +443,12 @@ abstract class MathRenderer {
 			}
 		}
 	}
+
+	/**
+	 * @return string original tex string specified by the user
+	 */
+	public function getUserInputTex(){
+		return $this->userInputTex;
+	}
 }
 
diff --git a/MathTexvc.php b/MathTexvc.php
index 1c69d47ca..89eb94ddc 100644
--- a/MathTexvc.php
+++ b/MathTexvc.php
@@ -110,7 +110,7 @@ class MathTexvc extends MathRenderer {
 	 * @return int|string MW_TEXVC_SUCCESS or error string
 	 */
 	public function callTexvc() {
-		global $wgTexvc, $wgTexvcBackgroundColor, $wgUseSquid, $wgMathCheckFiles, $wgHooks;
+		global $wgTexvc, $wgTexvcBackgroundColor, $wgHooks;
 
 		wfProfileIn( __METHOD__ );
 		$tmpDir = wfTempDir();
@@ -125,7 +125,7 @@ class MathTexvc extends MathRenderer {
 		$cmd = $wgTexvc . ' ' .
 			$escapedTmpDir . ' ' .
 			$escapedTmpDir . ' ' .
-			wfEscapeShellArg( $this->getTex() ) . ' ' .
+			wfEscapeShellArg( $this->getUserInputTex() ) . ' ' .
 			wfEscapeShellArg( 'UTF-8' ) . ' ' .
 			wfEscapeShellArg( $wgTexvcBackgroundColor );