diff --git a/libqpdf/QPDFJob_config.cc b/libqpdf/QPDFJob_config.cc
index 5dd8e29..d318d2d 100644
--- a/libqpdf/QPDFJob_config.cc
+++ b/libqpdf/QPDFJob_config.cc
@@ -1,11 +1,36 @@
 #include <qpdf/QPDFJob_private.hh>
 
-#include <regex>
-
 #include <qpdf/QPDFLogger.hh>
+#include <qpdf/QPDFUsage.hh>
 #include <qpdf/QTC.hh>
 #include <qpdf/QUtil.hh>
 
+#include <concepts>
+#include <regex>
+
+static void
+int_usage(std::string_view option, std::integral auto min, std::integral auto max)
+{
+    throw QPDFUsage(
+        "invalid "s.append(option) + ": must be a number between " + std::to_string(min) + " and " +
+        std::to_string(max));
+}
+
+static int
+to_int(std::string_view option, std::string const& value, int min, int max)
+{
+    int result = 0;
+    try {
+        result = std::stoi(value);
+        if (result < min || result > max) {
+            int_usage(option, min, max);
+        }
+    } catch (std::exception&) {
+        int_usage(option, min, max);
+    }
+    return result;
+}
+
 void
 QPDFJob::Config::checkConfiguration()
 {
@@ -131,14 +156,14 @@ QPDFJob::Config::compressStreams(std::string const& parameter)
 QPDFJob::Config*
 QPDFJob::Config::compressionLevel(std::string const& parameter)
 {
-    o.m->compression_level = QUtil::string_to_int(parameter.c_str());
+    o.m->compression_level = to_int("compression-level", parameter, 1, 9);
     return this;
 }
 
 QPDFJob::Config*
 QPDFJob::Config::jpegQuality(std::string const& parameter)
 {
-    o.m->jpeg_quality = QUtil::string_to_int(parameter.c_str());
+    o.m->jpeg_quality = to_int("jpeg-quality", parameter, 0, 100);
     return this;
 }
 
diff --git a/qpdf/qtest/arg-parsing.test b/qpdf/qtest/arg-parsing.test
index 128826c..4da865e 100644
--- a/qpdf/qtest/arg-parsing.test
+++ b/qpdf/qtest/arg-parsing.test
@@ -15,7 +15,7 @@ cleanup();
 
 my $td = new TestDriver('arg-parsing');
 
-my $n_tests = 30;
+my $n_tests = 32;
 
 $td->runtest("required argument",
              {$td->COMMAND => "qpdf --password minimal.pdf"},
@@ -175,5 +175,17 @@ foreach my $arg (@bad_enc)
                  $td->NORMALIZE_NEWLINES);
 }
 
+$td->runtest("bad compression-level",
+             {$td->COMMAND => "qpdf --compression-level=false minimal.pdf"},
+             {$td->REGEXP => "invalid compression-level: must be a number between 1 and 9",
+                  $td->EXIT_STATUS => 2},
+             $td->NORMALIZE_NEWLINES);
+
+$td->runtest("bad jpeg-quality",
+             {$td->COMMAND => "qpdf --jpeg-quality=101 minimal.pdf"},
+             {$td->REGEXP => "invalid jpeg-quality: must be a number between 0 and 100",
+                  $td->EXIT_STATUS => 2},
+             $td->NORMALIZE_NEWLINES);
+
 cleanup();
 $td->report($n_tests);