diff --git a/multimedia/graphics/assimp/files/assimp-3.3.1-install-pkgconfig.patch b/multimedia/graphics/assimp/files/assimp-3.3.1-install-pkgconfig.patch
new file mode 100644
index 0000000000..923fdd7e9e
--- /dev/null
+++ b/multimedia/graphics/assimp/files/assimp-3.3.1-install-pkgconfig.patch
@@ -0,0 +1,13 @@
+diff -Nuar a/assimp.pc.in b/assimp.pc.in
+--- a/assimp.pc.in	2020-01-12 14:56:40.000000000 +0300
++++ b/assimp.pc.in	2021-01-03 19:10:31.796879663 +0300
+@@ -1,7 +1,7 @@
+ prefix=@CMAKE_INSTALL_PREFIX@
+-exec_prefix=@CMAKE_INSTALL_PREFIX@/
++exec_prefix=@CMAKE_INSTALL_PREFIX@
+ libdir=@CMAKE_INSTALL_PREFIX@/@ASSIMP_LIB_INSTALL_DIR@
+-includedir=@CMAKE_INSTALL_PREFIX@/../include/@ASSIMP_INCLUDE_INSTALL_DIR@
++includedir=@CMAKE_INSTALL_PREFIX@/@ASSIMP_INCLUDE_INSTALL_DIR@/assimp
+ 
+ Name: @CMAKE_PROJECT_NAME@
+ Description: Import various well-known 3D model formats in an uniform manner.
diff --git a/multimedia/graphics/assimp/pspec.xml b/multimedia/graphics/assimp/pspec.xml
index b41972cee6..61e0276276 100644
--- a/multimedia/graphics/assimp/pspec.xml
+++ b/multimedia/graphics/assimp/pspec.xml
@@ -11,7 +11,9 @@
         <License>BSD</License>
         <Summary>A JavaScript 3D rendering API for Qt Quick</Summary>
         <Description>APIs are provided for C and C++. There are various bindings to other languages (C#, Java, Python, Delphi, D). Assimp also runs on Android and iOS.</Description>
+        <Archive sha1sum="f148ba31dc1e7e00e59cc09b25535af997dc1998" type="targz">https://github.com/assimp/assimp/archive/v5.0.1.tar.gz</Archive>
         <BuildDependencies>
+            <Dependency>ninja</Dependency>
             <Dependency>boost-devel</Dependency>
             <Dependency>cmake</Dependency>
             <Dependency>glib2-devel</Dependency>
@@ -20,7 +22,9 @@
             <Dependency>minizip-devel</Dependency>
             <Dependency>git</Dependency>
         </BuildDependencies>
-        <Archive sha1sum="f148ba31dc1e7e00e59cc09b25535af997dc1998" type="targz">https://github.com/assimp/assimp/archive/v5.0.1.tar.gz</Archive>
+        <Patches>
+            <Patch>assimp-3.3.1-install-pkgconfig.patch</Patch>
+        </Patches>
     </Source>
     <Package>
         <Name>assimp</Name>