diff --git a/syntax/just.vim b/syntax/just.vim
index 10933f5..c110c90 100644
--- a/syntax/just.vim
+++ b/syntax/just.vim
@@ -238,15 +238,19 @@ syn cluster justExprInInterp contains=@justExprBase,justName,justExprParenInInte
 
 syn cluster justExprFunc contains=@justBuiltInFunctions,justReplaceRegex,justExprParen
 
-syn match justImport /\v^import\ze%(\s|\\\n)+['"]@=/
+syn match justImport /\v^import%(%(\s|\\\n)*\?|%(\s|\\\n)+['"]@=)/ transparent
+   \ contains=justImportStatement,justOptionalFile
+syn match justImportStatement '^import' contained
 
 syn match justOldInclude "^!include\s.*$" contains=justOldIncludeDirective
 syn match justOldIncludeDirective "^!include" contained
 
-syn match justModule /\v^mod%(\s|\\\n)+\h\k*\s*%($|%(\s|\\\n)+['"]@=)/
-   \ transparent contains=justModStatement,justName
+syn match justModule /\v^mod%(%(\s|\\\n)*\?)?%(\s|\\\n)+\h\k*\s*%($|%(\s|\\\n)+['"]@=)/
+   \ transparent contains=justModStatement,justName,justOptionalFile
 syn match justModStatement '^mod' contained
 
+syn match justOptionalFile '\V?' contained
+
 hi def link justAlias                 Statement
 hi def link justAssignmentOperator    Operator
 hi def link justBacktick              Special
@@ -260,7 +264,7 @@ hi def link justConditional           Conditional
 hi def link justCurlyBraces           Special
 hi def link justExport                Statement
 hi def link justFunction              Function
-hi def link justImport                Include
+hi def link justImportStatement       Include
 hi def link justIndentError           Error
 hi def link justInterpolation         Normal
 hi def link justInterpolationDelim    Delimiter
@@ -271,6 +275,7 @@ hi def link justName                  Identifier
 hi def link justOldInclude            PreProc
 hi def link justOldIncludeDirective   Underlined
 hi def link justOperator              Operator
+hi def link justOptionalFile          Conditional
 hi def link justParameterError        Error
 hi def link justParameterOperator     Operator
 hi def link justParamExport           Statement
diff --git a/tests/cases/import.html b/tests/cases/import.html
index 210c500..c0db306 100644
--- a/tests/cases/import.html
+++ b/tests/cases/import.html
@@ -3,5 +3,5 @@
 <span class="Include">import</span><span class="Special">\</span>
 <span class="String">'line-continuations.just'</span>
 
-<span class="Include">import</span> 	<span class="String">"""</span>
+<span class="Include">import</span> <span class="Conditional">?</span>	<span class="String">"""</span>
 <span class="String">  tricky.just"""</span>
diff --git a/tests/cases/import.just b/tests/cases/import.just
index 3ebc3d2..39e633e 100644
--- a/tests/cases/import.just
+++ b/tests/cases/import.just
@@ -3,5 +3,5 @@ import 'recipes-simple.just'
 import\
 'line-continuations.just'
 
-import 	"""
+import ?	"""
   tricky.just"""
diff --git a/tests/cases/mod.html b/tests/cases/mod.html
index 0837997..520a800 100644
--- a/tests/cases/mod.html
+++ b/tests/cases/mod.html
@@ -7,3 +7,7 @@
 
 <span class="Keyword">mod</span> <span class="Identifier">_foo-Foo</span> <span class="Special">\</span>
   <span class="String">'foo/foo.just'</span>
+
+<span class="Keyword">mod</span><span class="Conditional">?</span> <span class="Identifier">foo</span>
+
+<span class="Keyword">mod</span> <span class="Conditional">?</span> <span class="Identifier">foo</span> <span class="String">'foo/justfile'</span>
diff --git a/tests/cases/mod.just b/tests/cases/mod.just
index a9fe0b1..a50cc78 100644
--- a/tests/cases/mod.just
+++ b/tests/cases/mod.just
@@ -7,3 +7,7 @@ mod foo "foo/justfile"
 
 mod _foo-Foo \
   'foo/foo.just'
+
+mod? foo
+
+mod ? foo 'foo/justfile'