diff --git a/src/input/readers/ascii/Ascii.cc b/src/input/readers/ascii/Ascii.cc
index 365336f93d..6d862fd1ca 100644
--- a/src/input/readers/ascii/Ascii.cc
+++ b/src/input/readers/ascii/Ascii.cc
@@ -6,7 +6,6 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <cerrno>
-#include <sstream>
 
 #include "zeek/input/readers/ascii/ascii.bif.h"
 #include "zeek/threading/SerialTypes.h"
@@ -345,7 +344,8 @@ bool Ascii::DoUpdate() {
                 FailWarn(fail_on_invalid_lines,
                          Fmt("Not enough fields in line '%s' of %s. Found "
                              "%d fields, want positions %d and %d",
-                             line.c_str(), fname.c_str(), pos, fit.position, fit.secondary_position));
+                             line.c_str(), fname.c_str(), pos, fit.position, fit.secondary_position),
+                         ! fail_on_invalid_lines);
 
                 if ( fail_on_invalid_lines ) {
                     for ( int i = 0; i < fpos; i++ )
@@ -374,8 +374,6 @@ bool Ascii::DoUpdate() {
             if ( fit.secondary_position != -1 ) {
                 // we have a port definition :)
                 assert(val->type == TYPE_PORT);
-                //	Error(Fmt("Got type %d != PORT with secondary position!", val->type));
-
                 val->val.port_val.proto = formatter->ParseProto(stringfields[fit.secondary_position]);
             }
 
@@ -395,8 +393,10 @@ bool Ascii::DoUpdate() {
             delete[] fields;
             continue;
         }
+        // If there's no error, then it makes sense to report the next error.
+        else
+            StopWarningSuppression();
 
-        // printf("fpos: %d, second.num_fields: %d\n", fpos, (*it).second.num_fields);
         assert(fpos == NumFields());
 
         if ( Info().mode == MODE_STREAM )
@@ -408,6 +408,7 @@ bool Ascii::DoUpdate() {
     if ( Info().mode != MODE_STREAM )
         EndCurrentSend();
 
+    StopWarningSuppression();
     return true;
 }
 
diff --git a/testing/btest/Baseline/scripts.base.frameworks.input.invalid-lines-duplicate/.stderrwithoutfirstline b/testing/btest/Baseline/scripts.base.frameworks.input.invalid-lines-duplicate/.stderrwithoutfirstline
new file mode 100644
index 0000000000..1b84bb3c2f
--- /dev/null
+++ b/testing/btest/Baseline/scripts.base.frameworks.input.invalid-lines-duplicate/.stderrwithoutfirstline
@@ -0,0 +1,5 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+warning: ..<...>/Input::READER_ASCII: ../input.log, line 3: Not enough fields in line 'hello' of ../input.log. Found 0 fields, want positions 1 and -1
+warning: ..<...>/Input::READER_ASCII: ../input.log, line 10: Not enough fields in line 'hello' of ../input.log. Found 0 fields, want positions 1 and -1
+received termination signal
+>>>
diff --git a/testing/btest/scripts/base/frameworks/input/invalid-lines-duplicate.zeek b/testing/btest/scripts/base/frameworks/input/invalid-lines-duplicate.zeek
new file mode 100644
index 0000000000..fd54f4c2e6
--- /dev/null
+++ b/testing/btest/scripts/base/frameworks/input/invalid-lines-duplicate.zeek
@@ -0,0 +1,50 @@
+# @TEST-EXEC: btest-bg-run zeek zeek -b %INPUT
+# @TEST-EXEC: btest-bg-wait 10
+# @TEST-EXEC: sed 1d .stderr > .stderrwithoutfirstline
+# @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff .stderrwithoutfirstline
+
+redef exit_only_after_terminate = T;
+redef InputAscii::fail_on_invalid_lines = F;
+
+@TEST-START-FILE input.log
+#fields	a	b	c
+#types	string	bool	bool
+hello
+hello
+hello
+hello
+hello
+hello
+"hi"	T	F
+hello
+hello
+hello
+hello
+hello
+hello
+hello
+@TEST-END-FILE
+
+type Key: record {
+    a: string;
+};
+
+type Val: record {
+    b: bool &log;
+    c: bool &log;
+};
+
+global test_table: table[string] of Val = table();
+
+event zeek_init() {
+    Input::add_table([
+        $source="../input.log", $name="test_table",
+        $idx=Key, $val=Val, $destination=test_table,
+        $mode=Input::REREAD
+    ]);
+}
+
+
+event Input::end_of_data(name: string, source:string) {
+	terminate();
+}