diff --git a/1991/davidguy/Makefile b/1991/davidguy/Makefile
index 7c18c7b82..6a7bb0120 100644
--- a/1991/davidguy/Makefile
+++ b/1991/davidguy/Makefile
@@ -40,7 +40,7 @@ include ../../var.mk
 #
 CSILENCE= -Wno-bitwise-op-parentheses -Wno-error -Wno-implicit-function-declaration \
 	-Wno-int-to-pointer-cast -Wno-return-type -Wno-sign-compare \
-	-Wno-deprecated-non-prototype
+	-Wno-deprecated-non-prototype -Wno-implicit-int
 
 # Common C compiler warning flags
 #
@@ -63,7 +63,7 @@ CDEFINE=
 
 # Include files that are needed to compile
 #
-CINCLUDE=
+CINCLUDE= -include sys/types.h -include sys/socket.h -include unistd.h
 
 # Optimization
 #
diff --git a/1991/davidguy/README.md b/1991/davidguy/README.md
index 81ac88c3f..3a927f703 100644
--- a/1991/davidguy/README.md
+++ b/1991/davidguy/README.md
@@ -106,15 +106,15 @@ be computed by a boolean circuit.  In addition, intermediate values
 computed by the circuit can be shared between neighboring cells,
 reducing the number of gates per cell required.  These ideas
 have been used before, to compute the next generation through a
-series of bit blits.  Instead of doing this, we map values in the
-circuit to bits in registers, so that the next generation can be
-computed efficiently within registers, minimizing memory accesses.
-As a result, the computation of the next generation is performed
-with about 1.6 instructions per life cell, consisting of .125
-memory accesses, .17 shifts, and 1.3 logic operations.  The net
-result is that the time to transfer the bits to the X server, and
-for the X server to draw them on the screen, dominates the time to
-compute the next generation.
+series of [bit blits](https://en.wikipedia.org/wiki/Bit_blit).
+
+Instead of doing this, we map values in the circuit to bits in registers, so
+that the next generation can be computed efficiently within registers,
+minimizing memory access.  As a result, the computation of the next generation
+is performed with about 1.6 instructions per life cell, consisting of .125
+memory accesses, .17 shifts, and 1.3 logic operations.  The net result is that
+the time to transfer the bits to the X server, and for the X server to draw them
+on the screen, dominates the time to compute the next generation.
 
 
 ## Copyright and CC BY-SA 4.0 License:
diff --git a/thanks-for-fixes.md b/thanks-for-fixes.md
index f8191f571..038657dad 100644
--- a/thanks-for-fixes.md
+++ b/thanks-for-fixes.md
@@ -1129,6 +1129,14 @@ him): `k` for forward, `h` for left and `l` for right. This version also has a
 more useful way to exit, just entering `q` followed by enter.
 
 
+## [1991/davidguy](1991/davidguy/davidguy.c) ([README.md](1991/davidguy/README.md]))
+
+As some systems like macOS can be particular about not declaring functions Cody
+added to the Makefile some `-include` options. These appear to not be strictly
+necessary but it was done due to other syscalls being a problem not being
+declared first.
+
+
 ## [1991/dds](1991/dds/dds.c) ([README.md](1991/dds/README.md]))
 
 Cody fixed a segfault that prevented this entry from working in any condition