diff --git a/cpu/trunk/easywave.h b/cpu/trunk/easywave.h
index 09ef8c03855656fd35402653d97a404261193bf6..fde0240e38ff4c7e98972b0f7601eadb1a493f94 100644
--- a/cpu/trunk/easywave.h
+++ b/cpu/trunk/easywave.h
@@ -88,4 +88,7 @@ int ewDumpPOIsCompact( int istage );
 
 extern CNode *gNode;
 
+/* unset to remove ZTOP_PATCH */
+#define ZTOP_PATCH
+
 #endif /* EASYWAVE_H */
diff --git a/cpu/trunk/ewSource.cpp b/cpu/trunk/ewSource.cpp
index 13ee2a77a4f2c8389ef521d8e826f07ba2cbba92..90b7d68fed8574cff2a7fc9e0df8e7c78a78466c 100644
--- a/cpu/trunk/ewSource.cpp
+++ b/cpu/trunk/ewSource.cpp
@@ -49,6 +49,31 @@ int ewSource()
     
     ierr = eq.read( Par.fileSource ); if(ierr) return ierr;
 
+#ifdef ZTOP_PATCH
+    // check fault parameters
+	Err.disable();
+	ierr = eq.finalizeInput();
+	while( ierr ) {
+	  i = ierr/10;
+	  ierr = ierr - 10*i;
+	  if( ierr == FLT_ERR_STRIKE ) {
+		Log.print( "No strike on input: Employing effective symmetric source model" );
+		if( eq.nfault > 1 ) { Err.enable(); return Err.post("Symmetric source assumes only 1 fault"); }
+		eq.fault[0].strike = 0.;
+		effSymSource = 1;
+	  }
+	  else if( ierr == FLT_ERR_ZTOP ) {
+		Log.print( "Automatic depth correction to fault top @ 10 km" );
+		eq.fault[i].depth = eq.fault[i].width/2 * sindeg(eq.fault[i].dip) + 10.e3;
+	  }
+	  else {
+		Err.enable();
+		return ierr;
+	  }
+	  ierr = eq.finalizeInput();
+	}
+	Err.enable();
+#else
     // check fault parameters
     Err.disable();
     ierr = eq.finalizeInput();
@@ -68,6 +93,7 @@ int ewSource()
       ierr = eq.finalizeInput(); if(ierr) return ierr;
     }
     Err.enable();
+#endif
 
     // calculate uplift on a rectangular grid
     // set grid resolution, grid dimensions will be set automatically