diff --git a/src/RE.cc b/src/RE.cc
index 3a790d2f4e..afb600bd4a 100644
--- a/src/RE.cc
+++ b/src/RE.cc
@@ -27,6 +27,8 @@ extern void RE_done_with_scan();
 namespace zeek {
 namespace detail {
 
+extern bool re_syntax_error;
+
 Specific_RE_Matcher::Specific_RE_Matcher(match_type arg_mt, bool arg_multiline)
     : mt(arg_mt), multiline(arg_multiline), equiv_class(NUM_SYM) {
     any_ccl = nullptr;
@@ -106,12 +108,13 @@ bool Specific_RE_Matcher::Compile(bool lazy) {
         return false;
 
     rem = this;
+    zeek::detail::re_syntax_error = false;
     RE_set_input(pattern_text.c_str());
 
     int parse_status = RE_parse();
     RE_done_with_scan();
 
-    if ( parse_status ) {
+    if ( parse_status || zeek::detail::re_syntax_error ) {
         reporter->Error("error compiling pattern /%s/", pattern_text.c_str());
         Unref(nfa);
         nfa = nullptr;
@@ -533,6 +536,35 @@ TEST_SUITE("re_matcher") {
         CHECK(dj->MatchExactly("def"));
         delete dj;
     }
+
+    TEST_CASE("synerr causes Compile() to fail") {
+        RE_Matcher match1("a{1,2}");
+        CHECK(match1.Compile());
+
+        RE_Matcher match2("a{6,5}");
+        CHECK_FALSE(match2.Compile());
+
+        RE_Matcher match3("a{1,a}");
+        CHECK_FALSE(match3.Compile());
+
+        RE_Matcher match4("a{1,2");
+        CHECK_FALSE(match4.Compile());
+
+        RE_Matcher match5("[1234");
+        CHECK_FALSE(match5.Compile());
+
+        RE_Matcher match6("a[1234}");
+        CHECK_FALSE(match6.Compile());
+
+        RE_Matcher match7("a\"b");
+        CHECK_FALSE(match7.Compile());
+
+        RE_Matcher match8("a\"b\"");
+        CHECK(match8.Compile());
+
+        RE_Matcher match9("a\\\"b");
+        CHECK(match9.Compile());
+    }
 }
 
 } // namespace zeek
diff --git a/src/re-parse.y b/src/re-parse.y
index 2d6672df8d..46ba7f91d1 100644
--- a/src/re-parse.y
+++ b/src/re-parse.y
@@ -9,10 +9,10 @@
 #include "zeek/EquivClass.h"
 #include "zeek/Reporter.h"
 
-int csize = 256;
-int syntax_error = 0;
 
 namespace zeek::detail {
+	constexpr int csize = 256;
+	bool re_syntax_error = 0;
 	int cupper(int sym);
 	int clower(int sym);
 }
@@ -230,7 +230,7 @@ ccl		:  ccl TOK_CHAR '-' TOK_CHAR
 
 ccl_expr:	   TOK_CCE
 			{
-			for ( int c = 0; c < csize; ++c )
+			for ( int c = 0; c < zeek::detail::csize; ++c )
 				if ( isascii(c) && $1(c) )
 					zeek::detail::curr_ccl->Add(c);
 			}
@@ -265,7 +265,7 @@ int clower(int sym)
 
 void synerr(const char str[])
 	{
-	syntax_error = true;
+	zeek::detail::re_syntax_error = true;
 	zeek::reporter->Error("%s (compiling pattern /%s/)", str, RE_parse_input);
 	}
 
diff --git a/src/re-scan.l b/src/re-scan.l
index f382393477..3056762ea7 100644
--- a/src/re-scan.l
+++ b/src/re-scan.l
@@ -149,9 +149,13 @@ CCL_EXPR	("[:"[[:alpha:]]+":]")
 }
 
 <SC_QUOTE>{
-	[^"\n]$		zeek::detail::synerr("missing quote"); return '"';
 	[^"\n]		yylval.int_val = yytext[0]; return TOK_CHAR;
 	\"		BEGIN(INITIAL); return '"';
+	<<EOF>>		{
+			zeek::detail::synerr("missing quote");
+			BEGIN(INITIAL);
+			return '"';
+			}
 }
 
 <SC_FIRST_CCL>{
@@ -164,8 +168,8 @@ CCL_EXPR	("[:"[[:alpha:]]+":]")
 	-/[^\]\n]	return '-';
 	[^\]\n]		yylval.int_val = yytext[0]; return TOK_CHAR;
 	"]"		BEGIN(INITIAL); return ']';
-	[^\]]$		{
-			zeek::detail::synerr("bad character class");
+	<<EOF>>		{
+			zeek::detail::synerr("unterminated character class");
 			BEGIN(INITIAL);
 			return ']';
 			}