diff --git a/src/jobs.lisp b/src/jobs.lisp
index ace8f76..2e0f2c4 100644
--- a/src/jobs.lisp
+++ b/src/jobs.lisp
@@ -57,7 +57,7 @@
 (defun initialize (&optional argv)
   "Initialize the jobs module."
   (format t "Initialize Job system~%")
-  (let ((thread-count (get-command-line-option-int argv "-j" 1)))
+  (let ((thread-count (get-command-line-option-number argv "-j" 1)))
     (when (> thread-count 0)
       (setf *thread-list*
             (make-array (list thread-count) :initial-contents
diff --git a/src/render/gl-utils.lisp b/src/render/gl-utils.lisp
index f58cca4..12ccfdd 100644
--- a/src/render/gl-utils.lisp
+++ b/src/render/gl-utils.lisp
@@ -30,7 +30,8 @@ Store values like the drivers version."
               *minor-version* min))
       (setf *major-version* (gl:get-integer :major-version)
             *minor-version* (gl:get-integer :minor-version)))
-  (setf *glsl-version* (gl:get-string :shading-language-version)))
+  (setf *glsl-version* (with-input-from-string (in (gl:get-string :shading-language-version))
+                         (read in))))
 
 (defun version-supported-p (version)
   (multiple-value-bind (maj min) (floor version 10)
diff --git a/src/render/render.lisp b/src/render/render.lisp
index e6e5afa..8c36423 100644
--- a/src/render/render.lisp
+++ b/src/render/render.lisp
@@ -37,9 +37,9 @@
 Create an opengl context attached to a window and initialize the shader system."
   (format t "Initialize Render module~%")
   (let ((title (get-command-line-option argv "--title" "Stoe"))
-        (width (get-command-line-option-int argv "--width" 800))
-        (height (get-command-line-option-int argv "--height" 600))
-        (version (get-command-line-option-int argv "--opengl")))
+        (width (get-command-line-option-number argv "--width" 800))
+        (height (get-command-line-option-number argv "--height" 600))
+        (version (get-command-line-option-number argv "--opengl")))
     (if version
         (progn
           (gl-utils:initialize version)
diff --git a/src/utils.lisp b/src/utils.lisp
index 2a1a702..089ebb3 100644
--- a/src/utils.lisp
+++ b/src/utils.lisp
@@ -17,7 +17,7 @@
            :make-clock :clock-time :clock-delta
            :update-clock :compare-clocks
            :get-command-line-option
-           :get-command-line-option-int))
+           :get-command-line-option-number))
 (in-package :stoe.utils)
 
 (declaim (optimize (debug 3) (safety 3) (speed 0)))
@@ -154,9 +154,12 @@
   (let ((opt (member optname argv :test #'equal)))
     (or opt default)))
 
-(defun get-command-line-option-int (argv optname &optional default)
-  "Return the option designated by `optname' from the command-line `argv'."
+(defun get-command-line-option-number (argv optname &optional default)
+  "Return the option designated by `optname' from the command-line `argv' as a number."
   (let ((opt (get-command-line-option argv optname)))
     (if opt
-        (parse-integer opt)
+        (let ((value (with-input-from-string (in opt)
+                       (read in))))
+          (assert (numberp value))
+          value)
         default)))