diff --git a/test/error/default_nettype_invalid.sv b/test/error/default_nettype_invalid.sv
index 196fd46..5352b72 100644
--- a/test/error/default_nettype_invalid.sv
+++ b/test/error/default_nettype_invalid.sv
@@ -1,3 +1,4 @@
+// pattern: bad default_nettype: "invalid"
 `default_nettype invalid
 module top;
     assign foo = 0;
diff --git a/test/error/default_nettype_none.sv b/test/error/default_nettype_none.sv
index e5e5cae..a2ef735 100644
--- a/test/error/default_nettype_none.sv
+++ b/test/error/default_nettype_none.sv
@@ -1,3 +1,4 @@
+// pattern: implicit declaration of "foo" but default_nettype is none
 `default_nettype none
 module top;
     assign foo = 0;
diff --git a/test/error/enum_conflict.sv b/test/error/enum_conflict.sv
index 1023842..a512498 100644
--- a/test/error/enum_conflict.sv
+++ b/test/error/enum_conflict.sv
@@ -1,3 +1,4 @@
+// pattern: enum conversion has duplicate vals
 module top;
     typedef enum {
         A = 0,
diff --git a/test/error/highz0_highz1.sv b/test/error/highz0_highz1.sv
index 385453b..5122776 100644
--- a/test/error/highz0_highz1.sv
+++ b/test/error/highz0_highz1.sv
@@ -1,3 +1,4 @@
+// pattern: unexpected token 'highz1'
 module top;
     wire (highz0, highz1) x;
 endmodule
diff --git a/test/error/lhs_expr.sv b/test/error/lhs_expr.sv
index 0ae5cd9..59313b9 100644
--- a/test/error/lhs_expr.sv
+++ b/test/error/lhs_expr.sv
@@ -1,3 +1,4 @@
+// pattern: cannot convert expression to LHS
 module top;
     logic x;
     assign {<< {x, 2'b00}} = 3'b101;
diff --git a/test/error/lhs_pattern.sv b/test/error/lhs_pattern.sv
index dceb913..70ac612 100644
--- a/test/error/lhs_pattern.sv
+++ b/test/error/lhs_pattern.sv
@@ -1,3 +1,4 @@
+// pattern: cannot convert expression to LHS
 module top;
     logic x, y, z;
     assign {<< {x, '{y:y, z:z}}} = 3'b101;
diff --git a/test/error/missing_include.sv b/test/error/missing_include.sv
index 3ae2df0..13a1873 100644
--- a/test/error/missing_include.sv
+++ b/test/error/missing_include.sv
@@ -1 +1,2 @@
+// pattern: Could not find file "does_not_exist\.sv", included from "missing_include\.sv"
 `include "does_not_exist.sv"
diff --git a/test/error/run.sh b/test/error/run.sh
index 0cca832..fb7a478 100755
--- a/test/error/run.sh
+++ b/test/error/run.sh
@@ -1,10 +1,25 @@
 #!/bin/bash
 
+validateOutput() {
+    stdout_len=`wc -l < $SHUNIT_TMPDIR/stdout`
+    assertEquals "stdout should be empty" 0 $stdout_len
+    stderr=`cat $SHUNIT_TMPDIR/stderr`
+    assertNotNull "stderr should not be empty" "$stderr"
+    line=`head -n1 $1`
+    if [[ "$line" =~ \/\/\ pattern:\ .* ]]; then
+        pattern=${line:12}
+        if [[ ! "$stderr" =~ $pattern ]]; then
+            fail "error message doesn't match\nexpected: $pattern\nactual: $stderr"
+        fi
+    fi
+}
+
 addTest() {
     test=$1
     eval "test_$test() { \
-        $SV2V $test.sv 2> /dev/null > /dev/null; \
+        $SV2V $test.sv 2> $SHUNIT_TMPDIR/stderr > $SHUNIT_TMPDIR/stdout; \
         assertFalse \"conversion should have failed\" \$?; \
+        validateOutput $test.sv; \
     }"
     suite_addTest test_$test
 }
diff --git a/test/error/undefined_macro.sv b/test/error/undefined_macro.sv
index a6ec448..395c3cb 100644
--- a/test/error/undefined_macro.sv
+++ b/test/error/undefined_macro.sv
@@ -1,3 +1,4 @@
+// pattern: Undefined macro: SOMETHING
 `SOMETHING
 module top;
 endmodule
diff --git a/test/error/unmatched_endif.sv b/test/error/unmatched_endif.sv
index 1d53b92..0e507c7 100644
--- a/test/error/unmatched_endif.sv
+++ b/test/error/unmatched_endif.sv
@@ -1 +1,2 @@
+// pattern: `endif directive outside of an `if/`endif block
 `endif