diff --git a/Changes b/Changes
index 078cfce4..9c8cd8a2 100644
--- a/Changes
+++ b/Changes
@@ -1,6 +1,11 @@
 Revision history for {{$dist->name}}
 
 {{$NEXT}}
+  - Alien::Base's Inline method once again returns only -I flags in
+    INC, with other compiler flags in CCFLAGSEX.  Inline::C was quoting
+    the combined flags as a single argument, which broke Aliens that have
+    non -I flags in their cflags.  ExtUtils::Depends, which only looks at
+    INC, still gets all of the compiler flags there (gh#430, gh#443)
 
 2.88      2026-09-19 03:03:10 -0600
   - Fixes for Solaris (gh#442)
diff --git a/lib/Alien/Base.pm b/lib/Alien/Base.pm
index 50b9e921..4599f8fc 100644
--- a/lib/Alien/Base.pm
+++ b/lib/Alien/Base.pm
@@ -915,18 +915,40 @@ sub inline_auto_include {
   $class->runtime_prop->{inline_auto_include} || $class->config('inline_auto_include') || []
 }
 
+sub _called_from_extutils_depends {
+  my $i = 0;
+  while(my $package = caller($i++)) {
+    return 1 if $package eq 'ExtUtils::Depends';
+  }
+  0;
+}
+
 sub Inline {
   my ($class, $language) = @_;
   return unless defined $language;
   return if $language !~ /^(C|CPP)$/;
   my $config = {
-    # INC should arguably be for -I flags only, but
-    # this improves compat with ExtUtils::Depends.
-    # see gh#107, gh#108
-    INC          => $class->cflags,
     LIBS         => $class->libs,
   };
 
+  if(_called_from_extutils_depends()) {
+    # ExtUtils::Depends piggybacks on this interface, but only
+    # looks at INC, LIBS and TYPEMAPS, so it needs all of the
+    # compiler flags in INC.  see gh#107, gh#108
+    $config->{INC} = $class->cflags;
+  } else {
+    # Inline::C quotes the whole of INC as a single argument if it
+    # contains spaces and anything other than -I flags.  see gh#430
+    # keep mode is used so that quotes and escapes survive the round trip.
+    my $cflags = $class->cflags;
+    $cflags = '' unless defined $cflags;
+    $cflags =~ s/^\s+//;
+    my @cflags = grep { defined $_ && length $_ } Text::ParseWords::parse_line('\s+', 1, $cflags);
+    $config->{INC} = join ' ', grep /^["']?-I/, @cflags;
+    my $ccflagsex  = join ' ', grep !/^["']?-I/, @cflags;
+    $config->{CCFLAGSEX} = $ccflagsex if length $ccflagsex;
+  }
+
   if (@{ $class->inline_auto_include } > 0) {
     $config->{AUTO_INCLUDE} = join "\n", map { "#include \"$_\"" } @{ $class->inline_auto_include };
   }
diff --git a/t/alien_base.t b/t/alien_base.t
index 232846bf..f1356be5 100644
--- a/t/alien_base.t
+++ b/t/alien_base.t
@@ -325,6 +325,67 @@ subtest 'build flags' => sub {
 
 };
 
+subtest 'Inline' => sub {
+
+  our $cflags;
+
+  {
+    package Alien::InlineTest;
+    use parent 'Alien::Base';
+    sub cflags { $cflags }
+    sub libs   { '-L/foo/lib -lfoo' }
+    sub inline_auto_include { [] }
+  }
+
+  {
+    package ExtUtils::Depends;
+    sub alien_base_test_load { Alien::InlineTest->Inline('C') }
+  }
+
+  is( Alien::InlineTest->Inline('Perl'), U(), 'unsupported language' );
+
+  subtest 'include flags only' => sub {
+    local $cflags = '-I/foo/include';
+    is(
+      Alien::InlineTest->Inline('C'),
+      { INC => '-I/foo/include', LIBS => '-L/foo/lib -lfoo' },
+    );
+  };
+
+  subtest 'mixed flags' => sub {
+    local $cflags = ' -I/foo/include -DBAR=1 -I/baz/include -O2 ';
+    is(
+      Alien::InlineTest->Inline('C'),
+      { INC => '-I/foo/include -I/baz/include', CCFLAGSEX => '-DBAR=1 -O2', LIBS => '-L/foo/lib -lfoo' },
+    );
+    is(
+      Alien::InlineTest->Inline('CPP'),
+      { INC => '-I/foo/include -I/baz/include', CCFLAGSEX => '-DBAR=1 -O2', LIBS => '-L/foo/lib -lfoo' },
+    );
+  };
+
+  subtest 'quotes and escapes are preserved' => sub {
+    local $cflags = q{-I"/foo bar/include" "-I/baz qux/include" -DSTR=\"x\" -IC:\foo\include};
+    is(
+      Alien::InlineTest->Inline('C'),
+      {
+        INC       => q{-I"/foo bar/include" "-I/baz qux/include" -IC:\foo\include},
+        CCFLAGSEX => q{-DSTR=\"x\"},
+        LIBS      => '-L/foo/lib -lfoo',
+      },
+    );
+  };
+
+  subtest 'called from ExtUtils::Depends' => sub {
+    local $cflags = '-I/foo/include -DBAR=1';
+    is(
+      ExtUtils::Depends::alien_base_test_load(),
+      { INC => '-I/foo/include -DBAR=1', LIBS => '-L/foo/lib -lfoo' },
+    );
+  };
+
+};
+
 subtest 'ffi_name' => sub {
 
   require Alien::libfoo1;