diff --git a/check/README.md b/check/README.md
index 268d72e9..87335037 100644
--- a/check/README.md
+++ b/check/README.md
@@ -239,6 +239,8 @@ The following methods are available in Ruby test programs.
   `true` if the FORM job finished within the timeout, otherwise `false`.
 - `succeeded? → bool`  
   `true` if the FORM job finished without any problems, otherwise `false`.
+- `valgrind_clean? → bool`  
+  `true` if no unexpected Valgrind errors are found, otherwise `false`.
 - `warning? → bool`  
   `true` if the FORM job issued a warning, otherwise `false`.
 - `warning?(expected_message : string) → bool`  
diff --git a/check/check.rb b/check/check.rb
index 835e5407..a998c492 100755
--- a/check/check.rb
+++ b/check/check.rb
@@ -799,6 +799,31 @@ def runtime_error?(expected_message = nil)
     end
   end
 
+  # true if no unexpected Valgrind errors are found.
+  def valgrind_clean?
+    if FormTest.cfg.valgrind.nil?
+      return true
+    end
+
+    # NOTE: we ignore invalid reads in TerminateImpl(), which are intentional
+    # in debug builds.
+    @stderr !~ /Invalid read(?![^\r\n]*\R[^\r\n]*\bTerminateImpl\b)/ &&
+      !@stderr.include?("Invalid write") &&
+      !@stderr.include?("Jump to the invalid address") &&
+      !@stderr.include?("Use of uninitialised value") &&
+      !@stderr.include?("Conditional jump or move depends on uninitialised value") &&
+      !@stderr.include?("points to unaddressable byte") &&
+      !@stderr.include?("points to uninitialised byte") &&
+      !@stderr.include?("contains uninitialised byte") &&
+      !@stderr.include?("Source and destination overlap in") &&
+      !@stderr.include?("Invalid free") &&
+      !@stderr.include?("Mismatched free") &&
+      !@stderr.include?("has a fishy") &&
+      @stderr !~ /definitely lost: [1-9]/ &&
+      @stderr !~ /indirectly lost: [1-9]/ &&
+      @stderr !~ /possibly lost: [1-9]/
+  end
+
   # true if the FORM job completed without any warnings/errors and
   # the exit code was 0.
   def succeeded?
@@ -808,28 +833,10 @@ def succeeded?
           return true
         end
 
-        @stdout += "!!! stderr is not empty"
         return false
       end
-      # Check for Valgrind errors.
-      ok = !@stderr.include?("Invalid read") &&
-           !@stderr.include?("Invalid write") &&
-           !@stderr.include?("Invalid free") &&
-           !@stderr.include?("Mismatched free") &&
-           !@stderr.include?("Use of uninitialised value") &&
-           !@stderr.include?("Conditional jump or move depends on uninitialised value") &&
-           !@stderr.include?("points to unaddressable byte") &&
-           !@stderr.include?("points to uninitialised byte") &&
-           !@stderr.include?("contains uninitialised byte") &&
-           !@stderr.include?("Source and destination overlap in memcpy") &&
-           !@stderr.include?("has a fishy") &&
-           @stderr !~ /definitely lost: [1-9]/ &&
-           @stderr !~ /indirectly lost: [1-9]/ &&
-           @stderr !~ /possibly lost: [1-9]/
-      if !ok
-        @stdout += "!!! Valgrind test failed"
-      end
-      return ok
+
+      return valgrind_clean?
     end
     false
   end