diff --git a/CMakeLists.txt b/CMakeLists.txt
index fb03cec..5a1b484 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -64,7 +64,7 @@ option(ENABLE_DEBUG "Should we build with Debug?" ON)
 option(ENABLE_DEBUG_DOSUTILS "Should we build with Mars Nwe Dosutils Debugging?" OFF)
 option(ENABLE_INTERNAL_RIP_SAP "Should we build Mars Nwe with Internal Router?" ON)
 option(ENABLE_SHADOW_PWD "Should we build Mars Nwe with Shadow Password Support?" ON)
-option(ENABLE_QUOTA_SUPPORT "Should we build Mars Nwe with Quota Support?" OFF)
+option(ENABLE_QUOTA_SUPPORT "Should we build Mars Nwe with Quota Support?" ON)
 option(ENABLE_XATTR "Should we build Mars Nwe with extended attribute support?" ON)
 option(MARS_NWE_INSTALL_DOSUTILS "Install DOS client utilities" ON)
 option(MARS_NWE_INSTALL_NEW_DOSUTILS "Install the new/experimental DOS client utilities instead of legacy netold.exe" OFF)
@@ -96,11 +96,12 @@ ELSE (ENABLE_SHADOW_PWD)
     SET (MARS_NWE_SHADOW_PWD "0")
 ENDIF (ENABLE_SHADOW_PWD)
 
-IF (ENABLE_QUOTA_SUPPORT)
+find_package(Quota QUIET)
+IF (ENABLE_QUOTA_SUPPORT AND QUOTA_FOUND)
     SET (MARS_NWE_QUOTA_SUPPORT "1")
-ELSE (ENABLE_QUOTA_SUPPORT)
+ELSE (ENABLE_QUOTA_SUPPORT AND QUOTA_FOUND)
     SET (MARS_NWE_QUOTA_SUPPORT "0")
-ENDIF (ENABLE_QUOTA_SUPPORT)
+ENDIF (ENABLE_QUOTA_SUPPORT AND QUOTA_FOUND)
 
 find_package(XAttr QUIET)
 IF (ENABLE_XATTR AND XATTR_FOUND)
@@ -128,6 +129,16 @@ find_package(OpenSSL REQUIRED)
 find_package(PAM REQUIRED)
 find_package(DL REQUIRED)
 
+if(MARS_NWE_QUOTA_SUPPORT)
+ message(STATUS "Quota support: enabled")
+else()
+ if(ENABLE_QUOTA_SUPPORT)
+  message(STATUS "Quota support: disabled (required headers/symbols not found)")
+ else()
+  message(STATUS "Quota support: disabled")
+ endif()
+endif()
+
 if(MARS_NWE_XATTR_SUPPORT)
  message(STATUS "XAttr support: enabled")
 else()
diff --git a/cmake/modules/FindQuota.cmake b/cmake/modules/FindQuota.cmake
new file mode 100644
index 0000000..956103d
--- /dev/null
+++ b/cmake/modules/FindQuota.cmake
@@ -0,0 +1,86 @@
+# - Find Linux quota support
+#
+# This module checks whether the system provides the headers and symbols
+# needed by mars_nwe's Linux user quota backend.
+#
+# It sets:
+#   QUOTA_FOUND              - true if usable quota support was found
+#   QUOTA_USE_SYS_QUOTA_H    - true if <sys/quota.h> should be used
+#   QUOTA_USE_LINUX_QUOTA_H  - true if <linux/quota.h> should be used
+#   QUOTA_HAVE_Q_SETQUOTA    - true if Q_SETQUOTA is available
+#   QUOTA_HAVE_Q_SETQLIM     - true if Q_SETQLIM is available
+#
+# Modern Linux/glibc systems declare quotactl() in <sys/quota.h>.  Prefer
+# that header.  Older systems may only have <linux/quota.h>, which is kept
+# as a fallback for the historical mars_nwe code path.
+
+include(CheckIncludeFile)
+include(CheckSymbolExists)
+
+set(QUOTA_FOUND FALSE)
+set(QUOTA_USE_SYS_QUOTA_H FALSE)
+set(QUOTA_USE_LINUX_QUOTA_H FALSE)
+
+check_include_file("sys/quota.h" QUOTA_HAVE_SYS_QUOTA_H)
+check_include_file("linux/quota.h" QUOTA_HAVE_LINUX_QUOTA_H)
+
+if(QUOTA_HAVE_SYS_QUOTA_H)
+  check_symbol_exists(quotactl "sys/types.h;sys/quota.h" QUOTA_HAVE_QUOTACTL_SYS)
+  check_symbol_exists(QCMD     "sys/types.h;sys/quota.h" QUOTA_HAVE_QCMD_SYS)
+  check_symbol_exists(Q_GETQUOTA "sys/types.h;sys/quota.h" QUOTA_HAVE_Q_GETQUOTA_SYS)
+  check_symbol_exists(USRQUOTA "sys/types.h;sys/quota.h" QUOTA_HAVE_USRQUOTA_SYS)
+  check_symbol_exists(Q_SETQUOTA "sys/types.h;sys/quota.h" QUOTA_HAVE_Q_SETQUOTA_SYS)
+  check_symbol_exists(Q_SETQLIM  "sys/types.h;sys/quota.h" QUOTA_HAVE_Q_SETQLIM_SYS)
+
+  if(QUOTA_HAVE_QUOTACTL_SYS AND QUOTA_HAVE_QCMD_SYS AND
+     QUOTA_HAVE_Q_GETQUOTA_SYS AND QUOTA_HAVE_USRQUOTA_SYS AND
+     (QUOTA_HAVE_Q_SETQUOTA_SYS OR QUOTA_HAVE_Q_SETQLIM_SYS))
+    set(QUOTA_FOUND TRUE)
+    set(QUOTA_USE_SYS_QUOTA_H TRUE)
+    set(QUOTA_HAVE_Q_SETQUOTA ${QUOTA_HAVE_Q_SETQUOTA_SYS})
+    set(QUOTA_HAVE_Q_SETQLIM  ${QUOTA_HAVE_Q_SETQLIM_SYS})
+  endif()
+endif()
+
+if(NOT QUOTA_FOUND AND QUOTA_HAVE_LINUX_QUOTA_H)
+  check_symbol_exists(QCMD     "linux/quota.h" QUOTA_HAVE_QCMD_LINUX)
+  check_symbol_exists(Q_GETQUOTA "linux/quota.h" QUOTA_HAVE_Q_GETQUOTA_LINUX)
+  check_symbol_exists(USRQUOTA "linux/quota.h" QUOTA_HAVE_USRQUOTA_LINUX)
+  check_symbol_exists(Q_SETQUOTA "linux/quota.h" QUOTA_HAVE_Q_SETQUOTA_LINUX)
+  check_symbol_exists(Q_SETQLIM  "linux/quota.h" QUOTA_HAVE_Q_SETQLIM_LINUX)
+
+  if(QUOTA_HAVE_QCMD_LINUX AND QUOTA_HAVE_Q_GETQUOTA_LINUX AND
+     QUOTA_HAVE_USRQUOTA_LINUX AND
+     (QUOTA_HAVE_Q_SETQUOTA_LINUX OR QUOTA_HAVE_Q_SETQLIM_LINUX))
+    set(QUOTA_FOUND TRUE)
+    set(QUOTA_USE_LINUX_QUOTA_H TRUE)
+    set(QUOTA_HAVE_Q_SETQUOTA ${QUOTA_HAVE_Q_SETQUOTA_LINUX})
+    set(QUOTA_HAVE_Q_SETQLIM  ${QUOTA_HAVE_Q_SETQLIM_LINUX})
+  endif()
+endif()
+
+if(QUOTA_FOUND)
+  if(QUOTA_USE_SYS_QUOTA_H)
+    message(STATUS "Found Quota: sys/quota.h")
+  else()
+    message(STATUS "Found Quota: linux/quota.h")
+  endif()
+else()
+  message(STATUS "Could NOT find Quota")
+endif()
+
+mark_as_advanced(
+  QUOTA_HAVE_SYS_QUOTA_H
+  QUOTA_HAVE_LINUX_QUOTA_H
+  QUOTA_HAVE_QUOTACTL_SYS
+  QUOTA_HAVE_QCMD_SYS
+  QUOTA_HAVE_Q_GETQUOTA_SYS
+  QUOTA_HAVE_USRQUOTA_SYS
+  QUOTA_HAVE_Q_SETQUOTA_SYS
+  QUOTA_HAVE_Q_SETQLIM_SYS
+  QUOTA_HAVE_QCMD_LINUX
+  QUOTA_HAVE_Q_GETQUOTA_LINUX
+  QUOTA_HAVE_USRQUOTA_LINUX
+  QUOTA_HAVE_Q_SETQUOTA_LINUX
+  QUOTA_HAVE_Q_SETQLIM_LINUX
+)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index ec6d833..b4d91ee 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -20,11 +20,13 @@ add_definitions(
         -D_VERS_P_=${VERSION_PATCH}
     )
 
-IF(ENABLE_QUOTA_SUPPORT)
-    add_definitions(
-	-DQTAINSYS
-    )
-ENDIF(ENABLE_QUOTA_SUPPORT)
+IF(MARS_NWE_QUOTA_SUPPORT)
+    IF(QUOTA_USE_SYS_QUOTA_H)
+        add_definitions(
+            -DQTAINSYS
+        )
+    ENDIF(QUOTA_USE_SYS_QUOTA_H)
+ENDIF(MARS_NWE_QUOTA_SUPPORT)
 
 IF(GDBM_FOUND)
     add_definitions(