diff --git a/coreutils/date.c b/coreutils/date.c
index 0fb9f1f..2c6e1d4 100644
--- a/coreutils/date.c
+++ b/coreutils/date.c
@@ -66,7 +66,7 @@
  * date [OPTION]... [+FORMAT]
  * date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
  * -d, --date=STRING
- *      display time described by STRING, not `now'
+ *      display time described by STRING, not 'now'
  * -f, --file=DATEFILE
  *      like --date once for each line of DATEFILE
  * -r, --reference=FILE
diff --git a/coreutils/echo.c b/coreutils/echo.c
index af33319..e45b909 100644
--- a/coreutils/echo.c
+++ b/coreutils/echo.c
@@ -218,7 +218,7 @@
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
diff --git a/coreutils/env.c b/coreutils/env.c
index 8def9c2..3242446 100644
--- a/coreutils/env.c
+++ b/coreutils/env.c
@@ -129,7 +129,7 @@
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
diff --git a/coreutils/nohup.c b/coreutils/nohup.c
index 8e28f90..df271c7 100644
--- a/coreutils/nohup.c
+++ b/coreutils/nohup.c
@@ -31,12 +31,12 @@
 
 /* Compat info: nohup (GNU coreutils 6.8) does this:
 # nohup true
-nohup: ignoring input and appending output to `nohup.out'
+nohup: ignoring input and appending output to 'nohup.out'
 # nohup true 1>/dev/null
 nohup: ignoring input and redirecting stderr to stdout
 # nohup true 2>zz
 # cat zz
-nohup: ignoring input and appending output to `nohup.out'
+nohup: ignoring input and appending output to 'nohup.out'
 # nohup true 2>zz 1>/dev/null
 # cat zz
 nohup: ignoring input
diff --git a/coreutils/od.c b/coreutils/od.c
index e3a6843..9a888dd 100644
--- a/coreutils/od.c
+++ b/coreutils/od.c
@@ -223,7 +223,7 @@
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE